Ownership Submission
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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(Print or Type Responses)
1. Name and Address of Reporting Person *
Flaherty James E
   2. Issuer Name and Ticker or Trading Symbol
Cardiovascular Systems Inc [CSII] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Administrative Officer
(Last)
(First)
(Middle)
651 CAMPUS DRIVE		 3. Date of Earliest Transaction (Month/Day/Year)
08/13/2010
(Street)

ST. PAUL, MN 55112		 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 Stock 08/13/2010   A   47,761 A $ 0 123,950 (1) D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Stock Option (right to buy) $ 8.83               (2) 12/18/2016 Common Stock 9,381   9,381 D  
Stock Option (right to buy) $ 8.83               (2) 04/17/2017 Common Stock 25,233   25,233 D  
Stock Option (right to buy) $ 7.9               (2) 08/06/2017 Common Stock 22,645   22,645 D  
Stock Option (right to buy) $ 12.15               (3) 12/11/2017 Common Stock 32,350   32,350 D  
Stock Option (right to buy) $ 8.75               (4) 03/02/2019 Common Stock 10,999   10,999 D  
Stock Option (right to buy) $ 9.28               (2) 11/15/2014 Common Stock 4,852   4,852 D  
Stock Option (right to buy) $ 12.37               (2) 06/30/2015 Common Stock 16,175   16,175 D  
Stock Option (right to buy) $ 12.37               (2) 11/07/2015 Common Stock 7,764   7,764 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Flaherty James E
651 CAMPUS DRIVE
ST. PAUL, MN 55112		       Chief Administrative Officer  

Signatures

 /s/ John R. Remakel as Attorney-in-Fact for James E. Flaherty pursuant to Power of Attorney previously filed.   08/17/2010
**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) Includes 1,315 shares acquired through the Issuer's Employee Stock Purchase Plan on June 30, 2010.
(2) Fully exercisable.
(3) Exercisable: 16,175 on 2/25/10 and 2/25/11.
(4) Exercisable: 5,500 on 3/2/10 and 5,499 on 3/2/11.

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