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): October 14, 2016

STR Holdings, Inc.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (860) 272-4235

(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 (see General Instruction A.2. below):

STR Holdings, Inc. (the “Company”) announced today that its manufacturing plant located in Shajiabang, Jiangsu, China suffered a fire that damaged a portion of its production facility. No employee injuries have been reported. The China facility’s production is currently shut down while the Company assesses the extent of the damage. Initial indications are that the damage was mainly to the mixing area of one production line, as well as to certain ancillary equipment and related systems. The Company does not anticipate delays in fulfilling customer orders as a result of the fire. The Company carries both casualty and property insurance for its facilities and equipment, as well as business interruption insurance, and is reviewing the extent and scope of this coverage with its insurance carriers. The Company’s other production facilities continue to operate in the normal course.

This report contains statements relating to our expected financial performance and/or future business prospects, events and plans that are “forward-looking statements” as defined under the Private Securities Litigation Reform Act of 1995. Forward-looking statements represent our estimates and assumptions only as of the date of this press release. The Company is currently assessing the scope of the damage to its facility and its property and its insurance coverage. The Company cannot guarantee that its insurance coverage, subject to applicable deductibles, is adequate to cover damage to the facility or other loss that the Company may suffer as a result of the fire. Nor can the Company guarantee that it will not experience delays in fulfilling customer orders. These forward-looking statements are subject to known and unknown risks and uncertainties that could cause actual results to differ materially from the results described in or anticipated by the Company’s forward-looking statements. The Company expressly disclaim any duty to provide updates to any forward-looking statements made in this report, whether as a result of new information, future events or otherwise.

The information in this report shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

SIGNATURE

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.