EXHIBIT 15.1     LETTER RE: UNAUDITED INTERIM FINANCIAL INFORMATION

Board of Directors and Shareholders
STERIS Corporation

            We are aware of the incorporation by reference in the following Registration Statements and related Prospectuses of our report dated July 18, 2002, relating to the unaudited consolidated interim financial statements of STERIS Corporation and Subsidiaries that are included in its Form 10-Q for the quarter ended June 30, 2002:

Registration Number	Description
333-91302	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Mark. D. McGinley
333-40058	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Les C. Vinney
333-40082	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Laurie Brlas and the Nonqualified Stock Option Agreement between STERIS Corporation and David L. Crandall
333-65155	Form S-8 Registration Statement — STERIS Corporation 1998 Long Term Incentive Compensation Plan
333-55839	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and John Masefield and the Nonqualified Stock Option Agreement between STERIS Corporation and Thomas J. DeAngelo
333-32005	Form S-8 Registration Statement — STERIS Corporation 1997 Stock Option Plan
333-06529	Form S-3 Registration Statement — STERIS Corporation
333-01610	Post-effective Amendment to Form S-4 on Form S-8 — STERIS Corporation
33-91444	Form S-8 Registration Statement — STERIS Corporation 1994 Equity Compensation Plan
33-91442	Form S-8 Registration Statement — STERIS Corporation 1994 Nonemployee Directors Equity Compensation Plan
33-55976	Form S-8 Registration Statement — STERIS Corporation 401(k) Plan
33-55258	Form S-8 Registration — STERIS Corporation Amended and Restated Non-Qualified Stock Option
333-63770	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Charles L. Immel and Restricted Shares Agreement between STERIS Corporation and Charles L. Immel
333-63772	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Thomas J. Magulski

Registration Number	Description
333-63774	Form S-8 Registration Statement — Nonqualified Stock Option Agreement between STERIS Corporation and Peter A. Burke

	/S/ ERNST & YOUNG LLP
Cleveland, Ohio August 13, 2002