Consent of Independent Registered Public Accounting Firm The Board of Directors First Niagara Financial Group, Inc. We consent to the incorporation by reference in the Registration Statements (No. 333-57736, No. 333-105525, and No. 333-105526) on Forms S-8 of First Niagara Financial Group, Inc. of our reports dated March 14, 2005, with respect to the consolidated statements of condition of First Niagara Financial Group, Inc. and subsidiary as of December 31, 2004 and 2003, and the related consolidated statements of income, comprehensive income, changes in stockholders' equity, and cash flows for each of the years in the three-year period ended December 31, 2004, management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2004 and the effectiveness of internal control over financial reporting as of December 31, 2004, which reports appear in the December 31, 2004 annual report on Form 10-K of First Niagara Financial Group, Inc. /s/ KPMG LLP Buffalo, New York March 14, 2005