FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Rosebrough Walter M Jr   2. Issuer Name and Ticker or Trading Symbol STERIS CORP [STE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President & CEO (Last) (First) (Middle) 5960 HEISLEY ROAD 3. Date of Earliest Transaction (Month/Day/Year) 05/23/2011 (Street) MENTOR, OH 44060 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Shares, No Par Value 05/23/2011   S(1)   3,400 D $ 35.0807 (2) 120,000 D   Common Shares, No Par Value 05/23/2011   F   7,668 (3) D $ 34.78 112,332 (4) D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Rosebrough Walter M Jr 5960 HEISLEY ROAD MENTOR, OH 44060	X		President & CEO

Signatures

Dennis P. Patton, Authorized Representative under Power of Attorney		05/25/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This open market sale of a total of 3,400 Common Shares is for the purpose of providing for the taxes payable upon the vesting of 24,000 restricted shares and is made pursuant to a Rule 10b5-1 Stock Trading Plan entered into by the Reporting Person on February 18, 2011.
(2)	This represents the average sales price of the shares sold. The actual 13 sales prices ranged from $34.99 per share to $35.21 per share. Issuer, upon request by the SEC staff, will provide full information regarding the number of shares sold at each of these 13 sales prices.
(3)	Mr. Rosebrough elected to have 7,668 shares withheld from the 24,000 restricted shares that were awarded to him on May 21, 2008 and which vested on May 23, 2011. These shares were valued as of the NYSE closing market price on May 23, 2011.
(4)	59,000 of these Common Shares are restricted. The restrictions on these Common Shares lapse as follows: 24,000 on May 21, 2012 and 35,000 on May 20, 2014.

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