Exhibit 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Nos. 333-02667, 333-77845, 333-95949, 333-36874 and 333-120450) and Form S-3ASR (No. 333-166710) of Omnicare, Inc., of our report dated February 23, 2012 relating to the financial statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Cincinnati, Ohio

February 23, 2012