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

For the transition period from                      to                     

Commission File Number 333-21873

FIRST INDUSTRIAL, L.P.

(Exact name of Registrant as specified in its Charter)

(312) 344-4300

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act: None

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  x    No  ¨

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  ¨    No  x

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 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 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, a non-accelerated filer, or a smaller reporting company. See the definitions 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

EXPLANATORY NOTE

First Industrial, L.P. (the “Operating Partnership”), is filing this Amendment No. 1 on Form 10-K/A (this “Amendment”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2011, which was originally filed on February 29, 2012 (the “Original Filing”), to amend Item 15 to include the separate financial statements of First Industrial Pennsylvania, L.P. as required under Rule 3-09 of Regulation S-X.

Other than as set forth herein, this Amendment does not affect any other parts of or exhibits to the Original Filing, and those unaffected parts or exhibits are not included in this Amendment. This Amendment continues to speak as of the date of the Original Filing and the Operating Partnership has not updated the disclosure contained herein to reflect events that have occurred since the filing of the Original Filing. Accordingly, this Amendment should be read in conjunction with the Operating Partnership’s other filings made with the Securities and Exchange Commission since the filing of the Original Filing, including amendments to those filings, if any.

Item 15. Exhibits and Financial Statement Schedules

(a) Financial Statements, Financial Statement Schedule and Exhibits

(1 & 2) See Index to Financial Statements and Financial Statement Schedule.

(3) Exhibits:

SIGNATURES

Pursuant to the requirements 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.

Date: February 28, 2013

Date: February 28, 2013