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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K/A

(Amendment No. 1)

For the Fiscal Year Ended June 30, 2010

or

For the Transition Period from                  to                 

Commission File No. 001-34727

TPC Group Inc.

(Exact name of registrant as specified in its charter)

5151 San Felipe, Suite 800

Houston, Texas 77056

(Address of principal executive offices, including zip code)

(713) 627-7474

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the 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  ¨    No  x

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

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 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  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ¨    No  ¨

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.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act:

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

The aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was approximately $63.8 million on December 31, 2009, based on $7.75, the last quotation on Pink OTC Markets on such date.

There were 18,255,698 shares of the registrant’s common stock outstanding as of September 10, 2010

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement for the 2010 Annual Meeting of Stockholders, to be filed no later than 120 days after the end of the fiscal year, are incorporated by reference into Part III of this Annual Report on Form 10-K.

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EXPLANATORY NOTE

TPC Group Inc. is filing this Amendment No. 1 on Form 10-K/A (the “Amendment No. 1”) to correct the item set forth below in our Annual Report on Form 10-K for the year ended June 30, 2010 filed with the Securities and Exchange Commission on September 17, 2010 (the “Original Filing”):

This Amendment No. 1 includes the following: Part IV, Item 15. Exhibits and Financial Statement Schedules, which includes the amended Consent of Grant Thornton LLP, and the Signatures.

Except for the item discussed in this Explanatory Note, no other changes have been made to the Original Filing. This Amendment No. 1 does not reflect events occurring after the Original Filing or modify or update disclosures affected by subsequent events.

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Part IV.

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PART IV

The following financial statements, schedules and exhibits are filed as part of this report:

INDEX TO EXHIBITS

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SIGNATURES

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

Each person whose signature appears below hereby constitutes and appoints Miguel A. Desdin and Christopher A. Artzer, and each of them, his true and lawful attorney-in-fact and agent, with full powers of substitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments to the Annual Report on Form 10-K for the fiscal year ended June 30, 2010, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission granting to said attorneys-in-fact, and each of them, full power and authority to perform any other act on behalf of the undersigned required to be done in connection therewith.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

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