New York                                                16-0816610
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(State of Incorporation                                       (I.R.S. Employer
        or Organization)                                     Identification No.)


         220 Liberty Street, Warsaw, New York                    14569
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         (Address of principal executive offices)                (Zip Code)

If this form relates to the registration of a class of debt securities and is to become effective simultaneously with the effectiveness of a concurrent registration statement under the Securities Act of 1933 pursuant to General Instruction A.(c)(2), please check the following box. |_|

If this form relates to the registration of a class of securities pursuant to
Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box. |_|

If this form relates to the registration of a class of securities pursuant to
Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box. |X|

Securities Act registration statement file number to which this form relates:

333-76865
(if applicable)

Securities to be registered pursuant to Section 12(b) of the Act:

Title of each class                               Name of each exchange on which
to be so Registered                               each class is to be registered
-------------------                               ------------------------------

--------------------------------            ------------------------------------

Securities to be registered pursuant to Section 12(g) of the Act:

ITEM 1. DESCRIPTION OF REGISTRANT'S SECURITIES TO BE REGISTERED.

The Registrant incorporates by reference herein the information set forth under the caption "Description of Securities of the Company" set forth in its preliminary prospectus dated June 23, 1999 included in Amendment No. 2 to its Registration Statement on Form S-1 (Registration No. 333-76865), filed with the Securities and Exchange Commission (the "Commission") on June 23, 1999, as such information may be amended in the final prospectus included or deemed to be included in such Registration Statement, as hereafter amended, in the form declared effective by the Commission (the "Registration Statement"). This Form 8-A is filed to register the Registrant's class of Common Stock pursuant to
Section 12(g) of the Securities Exchange Act of 1934, as amended ("Exchange Act"), concurrently with the registration of shares of Common Stock under the Securities Act of 1933, as amended ("Securities Act"), and in accordance with Rule 12d1-2 promulgated under the Exchange Act, will become effective concurrently with the effectiveness of the Registration Statement under the Securities Act.

Exhibit
Number                         Exhibit Name
------                         ------------

3.1        Amended and Restated Certificate of Incorporation of the Registrant
           is incorporated by reference to Exhibit 3.1 to the Registrant's
           Registration Statement on Form S-1 filed with the Securities and
           Exchange Commission, File No. 33-76865 (the "S-1")

3.2        By-laws of Registrant are incorporated by reference to Exhibit 3.2
           to the S-1

4.1        Form of Certificate of Registrant's Common Stock is incorporated by
           reference to Exhibit 4.1 to the S-1

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized.

Dated:     June 22, 1999                          FINANCIAL INSTITUTIONS, INC.


                                                  By:  /s/ Ronald A. Miller
                                                           Ronald A. Miller
                                                           Senior Vice President