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) September 7, 2012

RailAmerica, Inc.

(Exact Name of Registrant as Specified in Its Charter)

Delaware

(State or Other Jurisdiction of Incorporation)

7411 Fullerton Street, Suite 300, Jacksonville, Florida 32256

(Address of Principal Executive Offices) (Zip Code)

(855) 724-5444

(Registrant’s Telephone Number, Including Area Code)

N/A

(Former Name or Former Address, if Changed Since Last Report)

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:

Item 8.01. Other Events.

RailAmerica, Inc. (the Company) is filing this Current Report on Form 8-K to reflect the retrospective adoption of a new accounting pronouncement with respect to the financial information contained in its Annual Report on Form 10-K for the fiscal year ended December 31, 2011. As previously disclosed in the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2012 (filed with the Securities and Exchange Commission on April 26, 2012), the Company adopted Accounting Standard Update (ASU) No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income, which requires presentation of the components of net income and other comprehensive income either as one continuous statement or as two consecutive statements and eliminates the option to present components of other comprehensive income as part of the statement of changes in stockholders’ equity. The standard does not change the items that must be reported in other comprehensive income, how such items are measured or when they must be reclassified to net income.

Exhibit 99.1 presents the retrospective application of ASU 2011-05, as revised by ASU No. 2011-12, Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in Accounting Standards Update No. 2011-05, for the fiscal years ended December 31, 2011, 2010, and 2009, and should be read in conjunction with the information in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2011.

Item 9.01. Financial Statements, Pro Forma Financial Information and 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 hereunto duly authorized.

Exhibit Index