UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 10, 2012

QUESTCOR PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (714) 786-4200

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Questcor Pharmaceuticals, Inc. (the “Company”) held its 2012 Annual Meeting of Shareholders (the “Annual Meeting”) on Thursday, May 10, 2012, at its Northern California office, located at 26118 Research Place, Hayward, California 94545. At the Annual Meeting, the Company’s shareholders: (i) elected each of Don M. Bailey, Mitchell J. Blutt, M.D., Neal C. Bradsher, Stephen C. Farrell, Louis Silverman, Virgil D. Thompson and Scott M. Whitcup, M.D., to serve on the Company’s Board of Directors until the next annual meeting of shareholders and until the respective successor of each such director is duly elected and qualified, or until such director’s earlier death, resignation or removal (Proposal No. 1); (ii) approved, on a non-binding, advisory basis, the compensation of the Company’s named executive officers (Proposal No. 2); and (iii) ratified the appointment of BDO USA, LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2012 (Proposal No. 3).

As of March 20, 2012, the record date for the Annual Meeting, the Company had 63,284,779 shares of its common stock outstanding and entitled to vote. At the Annual Meeting, 55,256,570 shares of the Company’s common stock were present in person or represented by proxy and entitled to vote. The following sets forth detailed information regarding the voting results at the Annual Meeting:

Proposal No. 1: Election of seven directors to serve on the Company’s Board of Directors until the next annual meeting of shareholders and until his successor is duly elected and qualified, or until such director’s earlier death, resignation or removal. Each of the nominees received votes from greater than a majority of the Company’s outstanding shares of common stock.

Proposal No. 2: Approval, on a non-binding, advisory basis, of the compensation of the Company’s named executive officers.

Proposal No. 3: Ratification of the appointment of BDO USA, LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2012.

SIGNATURES

Pursuant to the requirements of the Exchange Act, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.