UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

                        For the fiscal year ended December 31, 2005

OR

Commission File Number 001-15875

King Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (423) 989-8000

Securities registered under Section 12(b) of the Exchange Act:

Securities registered under Section 12(g) of the Exchange Act:

None

      Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.     Yes þ          No o

      Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.     Yes o          No þ

      Indicate by check mark whether the registrant (1) filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     Yes þ  No o

      Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.     þ

      Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer þ          Accelerated filer o          Non-accelerated filer o

      Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).     Yes o          No þ

      The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common equity as of June 30, 2005 was $2,516,525,051 The number of shares of Common Stock, no par value, outstanding at February 27, 2006 was 242,080,103.

Documents Incorporated by Reference:

Certain information required in Part III of this Annual Report on Form 10-K is incorporated

by reference from the registrant’s Proxy Statement for its 2006 annual meeting of shareholders.

EXPLANATORY NOTE

      This Amendment No. 1 to the Annual Report on Form 10-K of King Pharmaceuticals, Inc. (the “Company”) amends the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2005, originally filed with the Securities and Exchange Commission on March 3, 2006 (the “Original Filing”). The Company is filing this Amendment No. 1 solely for the purpose of amending and restating Exhibit 23.1 (the consent of PricewaterhouseCoopers LLP, dated March 3, 2006) of the Original Filing.

      Except as described above, this Amendment No. 1 does not amend any other information set forth in the Original Filing and the Company has not updated disclosures contained therein to reflect any events that occurred at a date subsequent to the date of the Original Filing.

      Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as a result of this Amendment No. 1, the certifications pursuant to Section 302 and Section 906 of the Sarbanes-Oxley Act of 2002, included as exhibits to the Original Filing, have been amended, restated, re-executed and re-filed as of the date of this Amendment No. 1 and are included as Exhibits 31.1, 31.2, 32.1 and 32.2 hereto.

PART IV

(b) Exhibits

      The following Exhibits are filed herewith:

SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

March 8, 2006

      In accordance with the requirements of the Securities Exchange Act, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the date indicated.