Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 333-135954, 333-158755, 333-158987, 333-160609, 333-160610, 333-168682, 333-168684, 333-175702 and 333-175703) and on Form S-3 (No. 333-174681) of Cardiovascular Systems, Inc. of our report dated September 12, 2011 relating to the consolidated financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

Minneapolis, Minnesota

September 12, 2011