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): April 30, 2014

STERLING CONSTRUCTION COMPANY, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (281) 821-9091

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 (see General Instruction A.2. below):

Item 7.01 Regulation FD Disclosure.

On April 30, 2014, Sterling Construction Company, Inc. (the “Company”) issued a press release announcing that it had entered into an underwriting agreement relating to the agreement by D.A. Davidson & Co. to purchase 2,100,000 shares of the Company’s common stock, par value $0.01 per share, pursuant to an effective shelf registration statement. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

In accordance with General Instruction B.2 of Form 8-K, the press release shall not be deemed “filed” for the purposes of Section 18 of the Exchange Act of 1934, or otherwise subject to the liabilities of that section, nor shall such information and exhibit be deemed incorporated by reference into any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934 except as shall be expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements 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