FINANCIAL INSTITUTIONS INCREASES QUARTERLY DIVIDEND BY 20%

WARSAW, N.Y., May 25, 2011 — Financial Institutions, Inc. (Nasdaq: FISI) (the “Company”) announced today that its Board of Directors has declared a quarterly cash dividend of $0.12 per share of outstanding common stock, representing a 20% increase over the previous quarter’s dividend of $0.10 per share. The Company also announced dividends of $0.75 per share on Series A 3% Preferred Stock and $2.12 per share on Series B-1 8.48% Preferred Stock. All dividends are payable on July 5, 2011 to shareholders of record on June 17, 2011.

“The Company delivered exceptional performance in the opening quarter of 2011,” said Peter G. Humphrey, President and Chief Executive Officer. “Our solid underlying financial performance places us in a select group of community banks nationally, as evidenced by our inclusion among SNL Financial’s 100 best performing community banks for 2010, and Sandler O’Neill’s Sm-All Stars list of the top performing publicly-traded small-cap banks and thrifts in the nation. We are pleased to have increased our dividend, further enhancing shareholder value, while continuing to be a well-capitalized community bank serving the needs of our local communities.”

About Financial Institutions, Inc.

With over $2.2 billion in assets, Financial Institutions, Inc. provides diversified financial services through its subsidiaries, Five Star Bank and Five Star Investment Services, Inc. Five Star Bank provides a wide range of consumer and commercial banking services to individuals, municipalities and businesses through a network of over 50 offices and more than 70 ATMs in Western and Central New York State. Five Star Investment Services provides brokerage and insurance products and services within the same New York State markets. The consolidated entity employs over 600 individuals. Financial Institutions, Inc. was named to the 2010 Sandler O’Neill Sm-All Stars list of the top performing publicly-traded small-cap banks and thrifts in the nation and was included in the top 100 best performing community banks in the United States according to a ranking released in April 2011 by SNL Financial. The Company’s stock is listed on the Nasdaq Global Select Market under the symbol FISI. Additional information is available at the Company’s website: www.fiiwarsaw.com.

Safe Harbor Statement

This press release may contain forward-looking statements as defined by federal securities laws. These statements may address issues that involve significant risks, uncertainties, estimates and assumptions made by management. Actual results could differ materially from current beliefs or projections. There are a number of important factors that could affect the Company’s forward-looking statements which include its ability to implement its strategic plan, its ability to redeploy investment assets into loan assets, the attitudes and preferences of its customers, the competitive environment, fluctuations in the fair value of securities in the investment portfolio, changes in the regulatory environment and general economic and credit market conditions nationally and regionally. For more information about these factors please see the Company’s Annual Report on Form 10-K and its Quarterly Reports on Form 10-Q on file with the SEC. All of these factors should be carefully reviewed, and readers should not place undue reliance on these forward-looking statements. The Company undertakes no obligation to revise these statements following the date of this press release.

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