WESTAMERICA BANCORPORATION (the “Company”) is a bank holding company registered under the Bank Holding Company Act of 1956 (“BHC”), as amended. Its legal headquarters are located at 1108 Fifth Avenue, San Rafael, California 94901. Principal administrative offices are located at 4550 Mangels Boulevard in Fairfield, California 94534 and its telephone number is (707) 863-8000. The Company provides a full range of banking services to individual and corporate customers in Northern and Central California through its subsidiary bank, Westamerica Bank (“WAB” or the “Bank”). The principal communities served are located in Northern and Central California, from Mendocino, Lake, Colusa and Nevada Counties in the North to Kern County in the South. The Company’s strategic focus is on the banking needs of small businesses. In addition, the Company also owns 100% of the capital stock of Community Banker Services Corporation, a company engaged in providing the Company and its subsidiaries data processing services and other support functions.

      The Company was incorporated under the laws of the State of California in 1972 as “Independent Bankshares Corporation” pursuant to a plan of reorganization among three previously unaffiliated Northern California banks. The Company operated as a multi-bank holding company until mid-1983, at which time the then six subsidiary banks were merged into a single bank named Westamerica Bank and the name of the holding company was changed to Westamerica Bancorporation.

      The Company acquired five additional banks within its immediate market area during the early to mid 1990’s. In April, 1997, the Company acquired ValliCorp Holdings, Inc., parent company of ValliWide Bank, the largest independent bank holding company headquartered in Central California. Under the terms of all of the merger agreements, the Company issued shares of its common stock in exchange for all of the outstanding shares of the acquired institutions. The subsidiary banks acquired were merged with and into WAB. These business combinations were accounted for as poolings-of-interests.

      In August, 2000, the Company acquired First Counties Bank. The acquisition was valued at approximately $19.7 million and was accounted for using the purchase accounting method. The assets and liabilities of First Counties Bank were fully merged into WAB in September 2000. First Counties Bank had $91 million in assets and offices in Lake, Napa, and Colusa counties.

      In June of 2002 the Company acquired Kerman State Bank. The acquisition was valued at approximately $14.6 million and was accounted for using the purchase accounting method. The assets and liabilities of Kerman State Bank were fully merged into WAB immediately upon consummation of the merger. Kerman State Bank had $95 million in assets and three offices in Fresno county.

      At December 31, 2003, the Company had consolidated assets of approximately $4.6 billion, deposits of approximately $3.5 billion and shareholders’ equity of approximately $340.4 million. The Company and its subsidiaries employed 1,003 full-time equivalent staff.

      The Company makes available free of charge its annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and any amendments to those reports as well as beneficial ownership reports on Forms 3, 4 and 5 as soon as reasonably practicable after they are electronically filed with the Securities and Exchange Commission (“SEC”) through its website (http://www.westamerica.com). Such documents are also available through the SEC’s website (http://www.sec.gov). Requests for the Form 10-K annual report, as well as the Company’s employee Code of Conduct and Ethics, can also be submitted to:

	Westamerica Bancorporation
	Corporate Secretary A-2M
	Post Office Box 1200
	Suisun City, California 94585-1200

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Certain Additional Business Risks

      The Company’s business, financial condition and operating results can be impacted by a number of factors including, but not limited to, those set forth below, any one of which could cause the Company’s actual results to vary materially from recent results or from the Company’s anticipated future results.

      A portion of the loan portfolio of the Company is dependent on real estate. At December 31, 2003, real estate served as the principal source of collateral with respect to approximately 51% of the Company’s loan portfolio. A worsening of current economic conditions, increased economic uncertainty created by concerns regarding terrorist attacks and geo-political risks, or rising interest rates could have an adverse effect on the demand for new loans, the ability of borrowers to repay outstanding loans, the value of real estate and other collateral securing loans and the value of the available for sale securities portfolio, as well as the Company’s financial condition and results of operations in general and the market value of the Company’s common stock. Acts of nature, including earthquakes and floods, which may cause uninsured damage and other loss of value to real estate that secures these loans, may also negatively impact the Company’s financial condition and results of operations.

      The earnings and growth of the Company are affected not only by local market area factors and general economic conditions, but also by government monetary and fiscal policies. Such policies influence the growth of loans, investments and deposits and also affect interest rates charged on loans and paid on deposits. The nature and impact of future changes in such policies on the business and earnings of the Company cannot be predicted. Additionally, state and federal tax policies can impact banking organizations.

      As a consequence of the extensive regulation of commercial banking activities in the United States, the business of the Company is particularly susceptible to being affected by the enactment of federal and state legislation which may have the effect of increasing or decreasing the cost of doing business, modifying permissible activities or enhancing the competitive position of other financial institutions. Any change in applicable laws or regulations may have a material adverse effect on the business and prospects of the Company.

      The Company is also subject to certain operations risks, including, but not limited to, data processing system failures and errors and customer or employee fraud. The Company maintains a system of internal controls and procedures to mitigate against such occurrences and maintains insurance coverage for certain of such risks, but should such an event occur that is not prevented or detected by the Company’s internal controls, is not insured or is in excess of applicable insurance limits, it could have an adverse impact on the Company’s business, financial condition or results of operations.

      Shares of Company common stock eligible for future sale could have a dilutive effect on the market for Company common stock and could adversely affect the market price. The Articles of Incorporation of the Company authorize the issuance of 150 million shares of common stock (and two additional classes of 1 million shares each, denominated “Class B Common Stock” and “Preferred Stock”, respectively) of which approximately 32.3 million were outstanding at December 31, 2003. Pursuant to its stock option plans, at December 31, 2003, the Company had exercisable options outstanding of 1.90 million. As of December 31, 2003, 7.6 million shares of Company common stock remained available for grants under the Company’s stock option plans (and stock purchase plan). Sales of substantial amounts of Company common stock in the public market could adversely affect the market price of its common stock.

Supervision and Regulation

      The following is not intended to be an exhaustive description of the statutes and regulations applicable to the Company’s or the Bank’s business. The description of statutory and regulatory provisions is qualified in its entirety by reference to the particular statutory or regulatory provisions. Moreover, major new legislation and other regulatory changes affecting the Company, the Bank, banking, and the financial services industry in general have occurred in the last several years and can be expected to occur in the future. The nature, timing and impact of new and amended laws and regulations cannot be accurately predicted.

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      The Company is a bank holding company subject to the Bank Holding Company Act of 1956, as amended (the “BHCA”). The Company reports to, is registered with, and may be examined by, the Board of Governors of the Federal Reserve System (“FRB”). The FRB also has the authority to examine the Company’s subsidiaries. The costs of any examination by the FRB are payable by the Company. The Company is a bank holding company within the meaning of Section 3700 of the California Financial Code. As such, the Company and the Bank are subject to examination by, and may be required to file reports with, the California Commissioner of Financial Institutions (the “Commissioner”).

      The FRB has significant supervisory and regulatory authority over the Company and its affiliates. The FRB requires the Company to maintain certain levels of capital. See “Capital Standards.” The FRB also has the authority to take enforcement action against any bank holding company that commits any unsafe or unsound practice, or violates certain laws, regulations or conditions imposed in writing by the FRB. See “Prompt Corrective Action and Other Enforcement Mechanisms.” Under the BHCA, the Company is required to obtain the prior approval of the FRB before it acquires, merges or consolidates with any bank or bank holding company. Any company seeking to acquire, merge or consolidate with the Company also would be required to obtain the prior approval of the FRB.

      The Company is generally prohibited under the BHCA from acquiring ownership or control of more than 5% of the voting shares of any company that is not a bank or bank holding company and from engaging directly or indirectly in activities other than banking, managing banks, or providing services to affiliates of the holding company. However, a bank holding company, with the approval of the FRB, may engage, or acquire the voting shares of companies engaged, in activities that the FRB has determined to be closely related to banking or managing or controlling banks. A bank holding company must demonstrate that the benefits to the public of the proposed activity will outweigh the possible adverse effects associated with such activity.

      The FRB generally prohibits a bank holding company from declaring or paying a cash dividend that would impose undue pressure on the capital of subsidiary banks or would be funded only through borrowing or other arrangements which might adversely affect a bank holding company’s financial position. Under the FRB policy, a bank holding company should not continue its existing rate of cash dividends on its common stock unless its net income is sufficient to fully fund each dividend and its prospective rate of earnings retention appears consistent with its capital needs, asset quality and overall financial condition. See the section entitled “Restrictions on Dividends and Other Distributions” for additional restrictions on the ability of the Company and the Bank to pay dividends.

      Transactions between the Company and the Bank are restricted under Regulation W, which became effective on April 1, 2003. The regulation codifies prior interpretations of the FRB and its staff under Sections 23A and 23B of the Federal reserve Act. In general, subject to certain specified exemptions, a bank or its subsidiaries are limited in their ability to engage in “covered transactions” with affiliates: (a) to an amount equal to 10% of the bank’s capital and surplus, in the case of covered transactions with any one affiliate; and (b) to an amount equal to 20% of the bank’s capital and surplus, in the case of covered transactions with all affiliates. The Company is considered to be an affiliate of the Bank.

      A “covered transaction” includes, among other things, a loan or extension of credit to an affiliate; a purchase of securities issued by an affiliate; a purchase of assets from an affiliate, with some exceptions; and the issuance of a guarantee, acceptance or letter of credit on behalf of an affiliate.

      Federal regulations governing bank holding companies and change in bank control (Regulation Y) provide for a streamlined and expedited review process for bank acquisition proposals submitted by well-run bank holding companies. These provisions of Regulation Y are subject to numerous qualifications, limitations and restrictions. In order for a bank holding company to qualify as “well-run,” both it and the insured depository institutions which it controls must meet the “well capitalized” and “well managed” criteria set forth in Regulation Y.

      On March 11, 2000, the Gramm-Leach-Bliley Act (the “GLBA”), or the Financial Services Act of 1999 became effective. The GLBA repealed provisions of the Glass-Steagall Act, which had prohibited commercial banks and securities firms from affiliating with each other and engaging in each other’s businesses.

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      The BHCA was also amended by the GLBA to allow new “financial holding companies” (“FHCs”) to offer banking, insurance, securities and other financial products to consumers. Specifically, the GLBA amended section 4 of the BHCA in order to provide for a framework for the engagement in new financial activities. A bank holding company (“BHC”) may elect to become a FHC if all its subsidiary depository institutions are well capitalized and well managed. If these requirements are met, a BHC may file a certification to that effect with the FRB and declare that it elects to become a FHC. After the certification and declaration is filed, the FHC may engage either de novo or though an acquisition in any activity that has been determined by the FRB to be financial in nature or incidental to such financial activity. BHCs may engage in financial activities without prior notice to the FRB if those activities qualify under the new list of permissible activities in section 4(k) of the BHCA. However, notice must be given to the FRB within 30 days after a FHC has commenced one or more of the financial activities. The Company has not elected to become a FHC.

      Under the GLBA, Federal Reserve member banks, subject to various requirements, as well as national banks, are permitted to engage through “financial subsidiaries” in certain financial activities permissible for affiliates of FHCs. However, to be able to engage in such activities the Bank must also be well capitalized and well managed and have received at least a “satisfactory” rating in its most recent CRA examination. The Company cannot be certain of the effect of the foregoing recently enacted legislation on its business, although there is likely to be consolidation among financial services institutions and increased competition for the Company.

      The Bank is a California state-chartered bank, is insured by the Federal Deposit Insurance Corporation (the “FDIC”) and is a member bank of the Federal Reserve System. As such, the Bank is subject to regulation, supervision and regular examination by the California Department of Financial Institutions (“DFI”) and the FRB. As a member bank of the Federal Reserve System, the Bank’s primary federal regulator is the FRB. The regulations of these agencies affect most aspects of the Bank’s business and prescribe permissible types of loans and investments, the amount of required reserves, requirements for branch offices, the permissible scope of its activities and various other requirements.

      In addition to federal banking law, the Bank is also subject to applicable provisions of California law. Under California law, the Bank is subject to various restrictions on, and requirements regarding, its operations and administration including the maintenance of branch offices and automated teller machines, capital requirements, deposits and borrowings, stockholder rights and duties, and investment and lending activities.

      California law permits a state chartered bank to invest in the stock and securities of other corporations, subject to a state-chartered bank receiving either general authorization or, depending on the amount of the proposed investment, specific authorization from the Commissioner. However, because the Bank is a member of the Federal Reserve System, its investment authority is limited by regulations promulgated by the FRB. In addition, the Federal Deposit Insurance Corporation Improvement Act (“FDICIA”) imposes limitations on the activities and equity investments of state chartered, federally insured banks. FDICIA also prohibits a state bank from making an investment or engaging in any activity as a principal that is not permissible for a national bank, unless the Bank is adequately capitalized and the FDIC approves the investment or activity after determining that such investment or activity does not pose a significant risk to the deposit insurance fund.

      The federal banking agencies have risk-based capital adequacy guidelines intended to provide a measure of capital adequacy that reflects the degree of risk associated with a banking organization’s operations for both transactions reported on the balance sheet as assets, and transactions such as letters of credit and recourse arrangements, which are recorded as off balance sheet items. Under these guidelines, nominal dollar amounts of assets and credit equivalent amounts of off balance sheet items are multiplied by one of several risk

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      A banking organization’s risk-based capital ratios are obtained by dividing its qualifying capital by its total risk-adjusted assets and off balance sheet items.

      The federal banking agencies take into consideration concentrations of credit risk and risks from nontraditional activities, as well as an institution’s ability to manage those risks, when determining the adequacy of an institution’s capital. This evaluation is made as a part of the institution’s regular safety and soundness examination. The federal banking agencies also consider interest rate risk (when the interest rate sensitivity of an institution’s assets does not match the sensitivity of its liabilities or its off balance sheet position) in evaluation of a bank’s capital adequacy.

      As of December 31, 2003, the Company’s and the Bank’s respective ratios exceeded applicable regulatory requirements. See Note 8 to the consolidated financial statements for capital ratios of the Company and the Bank, compared to the standards for well capitalized depository institutions and for minimum capital requirements.

      FDICIA requires each federal banking agency to take prompt corrective action to resolve the problems of insured depository institutions, including but not limited to those that fall below one or more prescribed minimum capital ratios.

      An institution that, based upon its capital levels, is classified as “well capitalized,” “adequately capitalized” or “undercapitalized” may be treated as though it were in the next lower capital category if the appropriate federal banking agency, after notice and opportunity for hearing, determines that an unsafe or unsound condition or an unsafe or unsound practice warrants such treatment. At each successive lower capital category, an insured depository institution is subject to more restrictions. In addition to measures taken under the prompt corrective action provisions, commercial banking organizations may be subject to potential enforcement actions by the federal banking agencies for unsafe or unsound practices in conducting their businesses or for violations of any law, rule, regulation or any condition imposed in writing by the agency or any written agreement with the agency.

      FDICIA also implemented certain specific restrictions on transactions and required federal banking regulators to adopt overall safety and soundness standards for depository institutions related to internal control, loan underwriting and documentation and asset growth. Among other things, FDICIA limits the interest rates paid on deposits by undercapitalized institutions, restricts the use of brokered deposits, limits the aggregate extensions of credit by a depository institution to an executive officer, director, principal shareholder or related interest, and reduces deposit insurance coverage for deposits offered by undercapitalized institutions for deposits by certain employee benefits accounts. The federal banking agencies may require an institution to submit to an acceptable compliance plan as well as have the flexibility to pursue other more appropriate or effective courses of action given the specific circumstances and severity of an institution’s noncompliance with one or more standards.

      Federal banking agencies require banks to maintain adequate valuation allowances for potential credit losses. The Company has an internal staff that continually reviews loan quality and ultimately reports to the Board of Directors. This analysis includes a detailed review of the classification and categorization of problem loans, assessment of the overall quality and collectibility of the loan portfolio, consideration of loan loss experience, trends in problem loans, concentration of credit risk, and current economic conditions, particularly in the Bank’s market areas. Based on this analysis, management, with the review and approval of the Board, determines the adequate level of allowance required. The allowance is allocated to different segments of the loan portfolio, but the entire allowance is available for the loan portfolio in its entirety.

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      The power of the board of directors of an insured depository institution to declare a cash dividend or other distribution with respect to capital is subject to statutory and regulatory restrictions which limit the amount available for such distribution depending upon the earnings, financial condition and cash needs of the institution, as well as general business conditions. FDICIA prohibits insured depository institutions from paying management fees to any controlling persons or, with certain limited exceptions, making capital distributions, including dividends, if, after such transaction, the institution would be undercapitalized.

      In addition to the restrictions imposed under federal law, banks chartered under California law generally may only pay cash dividends to the extent such payments do not exceed the lesser of retained earnings of the bank or the bank’s net income for its last three fiscal years (less any distributions to shareholders during this period). In the event a bank desires to pay cash dividends in excess of such amount, the bank may pay a cash dividend with the prior approval of the Commissioner in an amount not exceeding the greatest of the bank’s retained earnings, the bank’s net income for its last fiscal year or the bank’s net income for its current fiscal year.

      The federal banking agencies also have the authority to prohibit a depository institution from engaging in business practices which are considered to be unsafe or unsound, possibly including payment of dividends or other payments under certain circumstances even if such payments are not expressly prohibited by statute.

      The Bank’s deposits are insured by the Bank Insurance Fund (BIF) administered by the FDIC. FDICIA established several mechanisms to increase funds to protect deposits insured by the BIF administered by the FDIC. The FDIC is authorized to borrow up to $30 billion from the United States Treasury; up to 90% of the fair market value of assets of institutions acquired by the FDIC as receiver from the Federal Financing Bank; and from depository institutions which are members of the BIF. Any borrowings not repaid by asset sales are to be repaid through insurance premiums assessed to member institutions. Such premiums must be sufficient to repay any borrowed funds within 15 years and provide insurance fund reserves of $1.25 for each $100 of insured deposits. FDICIA also provides authority for special assessments against insured deposits. No assurance can be given at this time as to what the future level of insurance premiums will be.

      The Bank is subject to certain fair lending requirements and reporting obligations involving home mortgage lending operations and Community Reinvestment Act (“CRA”) activities. The CRA generally requires the federal banking agencies to evaluate the record of a financial institution in meeting the credit needs of their local communities, including low and moderate income neighborhoods. In addition to substantive penalties and corrective measures that may be required for a violation of certain fair lending laws, the federal banking agencies may take compliance with such laws and CRA into account when regulating and supervising other activities.

      The GLBA, in addition to the previously described changes in permissible nonbanking activities permitted to banks, BHCs and FHCs, also required the federal banking agencies, among other federal regulatory agencies, to adopt regulations governing the privacy of consumer financial information. The FRB adopted such regulations with an effective date of November 13, 2000, and a date of full compliance with the regulations on July 1, 2001. The Bank is subject to the FRB,s regulations.

      On October 26, 2001, the President signed into law the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 or the “USA Patriot Act.” Title III of the Act is the International Money Laundering Abatement and Anti-Terrorist Financing Act of

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      The provisions of Title III of the USA Patriot Act which affect banking organizations, including the Bank, are generally set forth as amendments to the Bank Secrecy Act. These provisions relate principally to U.S. banking organizations’ relationships with foreign banks and with persons who are resident outside the United States. The USA Patriot Act does not immediately impose any new filing or reporting obligations for banking organizations, but does require certain additional due diligence and recordkeeping practices. Some requirements take effect without the issuance of regulations. Other provisions were implemented through regulations promulgated by the U.S. Department of the Treasury, in consultation with the FRB and other federal financial institutions regulators.

      On July 30, 2002, the U.S. Congress enacted the Sarbanes-Oxley Act of 2002 (“Sarbanes-Oxley”). The stated goals of Sarbanes-Oxley are to increase corporate responsibility, to provide for enhanced penalties for accounting and auditing improprieties at publicly traded companies and to protect investors by improving the accuracy and reliability of corporate disclosures pursuant to the securities laws. Sarbanes-Oxley generally applies to all companies, both U.S. and non-U.S., that file or are required to file periodic reports under the Securities Exchange Act of 1934 (the “Exchange Act”).

      Sarbanes-Oxley includes very specific additional disclosure requirements and new corporate governance rules, requires the SEC and securities exchanges to adopt extensive additional disclosure, corporate governance and other related rules and mandates further studies of certain issues. Sarbanes-Oxley represents significant federal involvement in matters traditionally left to state regulatory systems, such as the regulation of the accounting profession, and to state corporate law, such as the relationship between a board of directors and management and between a board of directors and its committees and public company shareholders.

      Sarbanes-Oxley addresses, among other matters: (i) independent audit committees for reporting companies whose securities are listed on national exchanges or automated quotation systems (the “Exchanges”) and expanded duties and responsibilities for audit committees; (ii) certification of financial statements by the chief executive officer and the chief financial officer; (iii) the forfeiture of bonuses or other incentive-based compensation and profits from the sale of an issuer’s securities by directors and senior officers in the twelve month period following initial publication of any financial statements that later require restatement; (iv) a prohibition on insider trading during pension plan black out periods; (v) disclosure of off-balance sheet transactions; (vi) a prohibition on personal loans to directors and officers under most circumstances; (vii) expedited electronic filing requirements related to trading by insiders in an issuer’s securities on Form 4; (viii) disclosure of a code of ethics and filing a Form 8-K for a change or waiver of such code; (ix) accelerated filing of periodic reports; (x) the formation of the Public Company Accounting Oversight Board (“PCAOB”) to oversee public accounting firms and the audit of public companies that are subject to the securities laws; (xi) auditor independence; (xii) internal control evaluation and reporting; and (xiii) various increased criminal penalties for violations of securities laws.

      Given the extensive role of the SEC, the PCAOB and the Exchanges in implementing rules relating to Sarbanes-Oxley’s new requirements, the federalization of certain elements traditionally within the sphere of state corporate law, the impact of Sarbanes-Oxley on reporting companies will be significant. Many of the new rules promulgated by the SEC, PCAOB and Exchanges became final during 2003 and will be implemented during 2004. As a result, it is impossible to predict with any precision how these new rules, regulations and changes in corporate law and governance will finally impact public companies including the Company.

      Certain pending legislative proposals include bills to permit banks to pay interest on business checking accounts, to cap consumer liability for stolen debit cards, to end certain predatory lending practices, to allow the payment of interest on reserves that financial institutions must keep with FRB and to give judges the

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Competition

      In the past, WAB’s principal competitors for deposits and loans have been other banks (particularly major banks), savings and loan associations and credit unions. To a lesser extent, competition was also provided by thrift and loans, mortgage brokerage companies and insurance companies. Other institutions, such as brokerage houses, mutual fund companies, credit card companies, and certain retail establishments have offered investment vehicles which also compete with banks for deposit business. Federal legislation in recent years has encouraged competition between different types of financial institutions and fostered new entrants into the financial services market, and it is anticipated that this trend will continue.

      The enactment of the Interstate Banking and Branching Act in 1994 and the California Interstate Banking and Branching Act of 1995 have increased competition within California. Regulatory reform, as well as other changes in federal and California law will also affect competition. While the impact of these changes, and of other proposed changes, cannot be predicted with certainty, it is clear that the business of banking in California will remain highly competitive.

      Legislative changes, as well as technological and economic factors, can be expected to have an ongoing impact on competitive conditions within the financial services industry. As an active participant in the financial markets, the Company believes that it continually adapts to these changing competitive conditions.

      According to information obtained through an independent market research firm, WAB was the eighth largest commercial banking company headquartered in California in terms of total assets in the third quarter of 2003. In the individual markets in which it has branch offices, WAB was the third largest financial institution. The share of individual markets within the overall market varies, with the most dominant continuing to be in the San Rafael area of Marin County where WAB ranked first in core deposits among federally-insured depository institutions.