Exhibit 32.1

          CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED
            PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Financial Institutions, Inc. (the
"Company") on Form 10-Q for the period ending September 30, 2003 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Peter G. Humphrey, Chief Executive Officer of the Company, certify, pursuant to
18 U.S.C. ss. 1350, as adopted pursuant to ss. 906 of the Sarbanes-Oxley Act of
2002, that:

      (1) The Report fully complies with the requirements of Section 13(a) or
      15(d) of the Securities Exchange Act of 1934; and

      (2) The information contained in the Report fairly presents, in all
      material respects, the financial condition and result of operations of the
      Company.

November 13, 2003


/s/ Peter G. Humphrey
- -----------------------------------

Peter G. Humphrey
President, Chief Executive Officer
(Principal Executive Officer),
Chairman of the Board and Director

A signed original of this written statement required by Section 906 has been
provided to the Company and will be retained by the Company and furnished to the
Securities and Exchange Commission or its staff upon request.