UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10–K/A

(Amendment No. 1)

For the fiscal year ended December 31, 2011

OR

Commission File Number 001-35010

QR ENERGY, LP

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (713) 452-2200

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 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 (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    YES  x    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 or any amendment to the Form 10–K.    x

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b–2 of the Exchange Act).    YES  ¨    NO  x

As of June 30, 2011, the last business day of the registrant’s most recently completed second fiscal quarter; the aggregate market value of the Common Units held by non-affiliates was approximately $356,252,000, based on the closing price of $20.64 per unit on that date. For purposes of this calculation, QA Holdings, LP, which owned 11,297,737 Common Units on such date, is considered an affiliate of the registrant.

As of March 15, 2012, the registrant had 16,666,667 Class C Convertible Preferred Units, 28,590,016 Common Units, 7,145,866 Subordinated Units and 35,729 General Partner Units outstanding.

EXPLANATORY NOTE

The purpose of this Amendment No. 1 (this “Amendment”) to the Annual Report on Form 10-K of QR Energy, LP (the “Partnership”) for the year ended December 31, 2011, as originally filed with the Securities and Exchange Commission (the “SEC”) on March 15, 2012 (the “Original 10-K Filing”), is to amend and restate in its entirety the information in the Exhibit Index included in Part IV, Item 15(a)(3) of the Original 10-K Filing (the “Original Exhibit Index”). The Partnership’s press release announcing earnings information for the fourth quarter of 2011, which was furnished as Exhibit 99.1 to our Current Report on Form 8-K filed on March 15, 2012, was inadvertently included as Exhibit 99.2 of the Original Exhibit Index.

Exhibit 99.2 filed with this Amendment contains certain supplementary unaudited financial information related to our three months ended December 31, 2011. Additionally, Exhibits 23.3 and 99.3 were inadvertently excluded from the Original Exhibit Index and are being filed herewith. Exhibit 23.3 contains the consent of Miller and Lents, Ltd. and Exhibit 99.3 contains the Report of Miller and Lents, Ltd., both of with relate to the reserve information of the Fund (as such term is defined in the Original 10-K Filing).

As required by Rule 12b-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), new certifications of our principal executive officer and principal financial officer are being filed or furnished, as indicated, as exhibits to this Amendment. Other than to file Exhibits 23.3, 99.2 and 99.3, and the new certifications included as Exhibits 31.1, 31.2, 32.1 and 32.2, there are no changes from the Original Exhibit Index reflected in Item 15 of this Amendment.

Except as described above, this Amendment does not modify or update the disclosures presented in the Original 10-K Filing in any way. Those sections of the Original 10-K Filing that are unaffected by this Amendment are not included herein. This Amendment continues to speak only as of the date of the Original 10-K Filing and it has no impact on the Partnership’s previously reported audited financial statements and notes thereto as of December 31, 2011. Furthermore, except to the extent stated herein, we have not updated the information in the Original 10-K Filing, and this Amendment does not reflect events occurring after the filing of the Original 10-K Filing. Accordingly, this Amendment should be read in conjunction with the Original 10-K Filing as well as the Partnership’s other filings made with the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act subsequent to the filing of the Original 10-K Filing as information in such filings may update or supersede certain information contained in the Original 10-K Filing, as amended hereby.

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PART IV

(a)(3) 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.

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 indicated on March 26, 2012.

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