Exhibit 99.1

STR HOLDINGS, INC. REPORTS FOURTH QUARTER AND FULL YEAR 2011 RESULTS

ENFIELD, Conn. — March 13, 2012 — STR Holdings, Inc. (NYSE: STRI) today announced financial and operating performance for the fourth quarter and year ended December 31, 2011.

Fourth Quarter 2011 Financial Summary:

·                  Q4 net sales of $36.5 million down 47.1% year over year and 35.0% sequentially

·                  Q4 diluted GAAP EPS from continuing operations of ($1.67); Q4 diluted non-GAAP EPS from continuing operations of ($0.05)

·                  Recorded a $63.9 million non-cash goodwill impairment

2011 Financial Summary:

·                  Prior Quality Assurance (QA) segment presented as discontinued operations

·                  2011 net sales of $232.4 million, down 10.3% from 2010

·                  2011 gross margin of 31.0% compared to 41.4% a year ago

·                  2011 diluted GAAP EPS from continuing operations of ($0.96); 2011 diluted non-GAAP EPS from continuing operations of $0.80

·                  2011 operating cash flow of $46.8 million and free cash flow of $25.3 million, both from continuing operations

·                  Finished the year with $58.8 million in cash and no debt

Financial Results

Net sales for the quarter ended December 31, 2011 were $36.5 million. This represents a decline of 35.0% sequentially and 47.1% from a year ago. These results were driven by a decrease in sales volume of 29% from the third quarter of this year and 41% from a year ago. Lower average selling price (ASP) also contributed to the decline as ASPs were lower by approximately 9% sequentially and 11% from a year ago.

“Although there was a surge in German installations during December, we believe much of the demand was satisfied by existing channel inventory,” said Robert S. Yorgensen, STR’s President and Chief Executive Officer. “Inventory clearing has reduced module prices to where we should begin to see demand elasticity. We expect to see our customers’ order patterns for our encapsulants return to growth over the course of 2012.”

5

Gross profit for the fourth quarter of 2011 was $4.2 million or 11.6% as a percentage of sales.  This is compared to $14.6 million or 25.9% as a percentage of sales from the previous sequential quarter. This gross profit decline was driven mostly by the decrease in volume, lower ASP and unfavorable mix.

Selling, general and administrative expenses (SG&A) were $8.7 million in the fourth quarter, a $1.9 million increase sequentially. The increase was mostly due to several discrete items including the unfavorable resolution of a sales tax audit, additional environmental remediation efforts and costs associated with the Company’s Asia expansion.

Lower gross profit and a non-cash goodwill impairment of $63.9 million drove an operating loss of $68.3 million, compared to a profit of $6.4 million in the third quarter of 2011 and $22.1 in the fourth quarter of 2010. The non-cash goodwill impairment was attributable to the decline in solar market conditions and the market capitalization of the Company’s common stock.

Net loss from continuing operations for the fourth quarter of 2011 was $68.5 million or $1.67 on a diluted EPS basis. This is compared with net earnings from continuing operations of $3.8 million, or $0.09 per diluted share for the third quarter of 2011 and $14.7 million or $0.35 per diluted share for the fourth quarter of 2010.

Non-GAAP net loss from continuing operations, which excludes certain tax-effected adjustments (as disclosed after the non-GAAP reconciliation table at the end of this press release) was $1.9 million, or $0.05 per share. This is compared to non-GAAP EPS of $0.21 in the third quarter of 2011, and $0.36 in the fourth quarter of 2010.

Additionally, during February 2012, the Company settled its legal dispute over the misappropriation of STR’s trade secrets. The Company has received a related payment of $7.2 million, all federal and state court actions have been dismissed and the defendants are permanently barred from using STR’s trade secret technology.

“We are pleased to conclude this dispute,” said Mr. Yorgensen. “The court ruling and subsequent settlement confirms STR’s reputation for distinctive technological expertise and the important technical advantages provided by our encapsulants.  This resolution frees up valuable time and resources and further improves the Company’s strong liquidity position.”

Balance Sheet and Liquidity

STR strengthened its balance sheet during the fourth quarter by generating $25.8 million in operating cash flow from continuing operations. This resulted from lower volume and tight working capital control, as the Company reduced its accounts receivables and raw material inventory. It finished the year with $58.8 million of cash and no debt. The reduction in cash from Q3 2011 is driven by $91.5 million of cash used in discontinued operations, of which the majority is due to taxes paid on the gain from the sale of QA. Capital expenditures amounted to $3.1 million for the quarter.

“We believe our strong balance sheet will allow us to capitalize on opportunities that we identify during this industry down cycle. We are intensely focused on controlling our costs and improving working

6

capital as we weather this difficult environment,” stated Barry A. Morris, STR’s Executive Vice President and Chief Financial Officer.

Guidance

The Company estimates that the first quarter of 2012 will be negatively impacted by demand for modules continually being supplied from existing inventory and seasonal slowness. The Company expects orders for its encapsulants to normalize during the second half of the year.

Based on the above, the Company today provided guidance for the first quarter and full-year 2012 as follows:

Amounts in millions, except per share amounts

Fourth Quarter Conference Call and Presentation

The Company will discuss its financial results and guidance in a conference call today at 4:30 p.m. ET. A live webcast of the conference call and presentation will be available through the Investor Relations section of the Company’s website at www.strholdings.com. Investors accessing the live call by phone from the U.S. should dial 800-561-2693 and enter passcode: 99225578. Those calling from outside the U.S. should dial 617-614-3523 and use the same passcode. A telephone replay will be available approximately two hours after the call concludes through Tuesday, March 20, 2012 by dialing 888-286-8010 from the U.S., or 617-801-6888 from international locations, and entering passcode: 26599417. The webcast and presentation will be archived on the Company’s website for one year.

About STR Holdings, Inc.

STR Holdings, Inc. is a leading global provider of high quality, superior performance encapsulants to the photovoltaic module industry. Further information about STR Holdings, Inc. can be obtained via the Company’s website at www.strholdings.com.

Forward-Looking Statements

This press release and any oral statement made in respect of the information in this press release contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are subject to inherent risks and uncertainties. These forward-looking statements present the Company’s current expectations and projections relating to its financial condition, results of operations, plans, objectives, future performance and business and are based on assumptions that the Company has made in light of its industry experience and perceptions of historical trends, current conditions, expected future developments and other factors management believes are appropriate under

7

the circumstances.  However, these forward-looking statements are not guarantees of future performance or financial or operating results. In addition to the risks and uncertainties discussed in this release, the Company faces risks and uncertainties that include, but are not limited to, the following: (i) demand for solar energy in general and solar modules in particular; (ii) the timing and effects of the implementation of government incentives and policies for renewable energy, primarily in China and the United States; (iii) the effects of the announced reductions to solar incentives in Germany and Italy; (iv) the extent to which we may be required to write-off accounts receivable or inventory; (v) pricing pressures and other competitive factors; (vi) our ability to protect our intellectual property; (vii) volatility in commodity costs, such as resin or paper used in our encapsulants, and our ability to successfully manage any increases in these commodity costs; (viii) our dependence on a limited number of third party suppliers for raw materials for our encapsulants and materials used in our processes; (ix) customer concentration in our business and our relationships with key customers; (x) operating new manufacturing facilities and increasing production capacity at existing facilities; (xi) our reliance on vendors and potential supply chain disruptions, including those resulting from bankruptcy filings by customers or vendors; (xii) potential product performance matters and product liability; (xiii) the extent and duration of the current downturn in the global economy; (xiv) the impact negative credit markets may have on us or our customers or suppliers; (xv) the impact of changes in foreign currency exchange rates on financial results, and the geographic distribution of revenues and earnings; (xvi) maintaining sufficient liquidity in order to fund future profitable growth and long-term vitality; (xvii) outcomes of litigation and regulatory actions; and (xix) other risks and uncertainties described under “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and in subsequent periodic reports on Forms 10-K, 10-Q and 8-K. You are urged to carefully review and consider the disclosure found in the Company’s filings which are available on www.sec.gov or www.strholdings.com. Should one or more of these risks or uncertainties materialize, or should any of these assumptions prove to be incorrect, actual results may vary materially from those projected in these forward-looking statements. The Company undertakes no obligation to publicly update any forward-looking statements contained in this release, whether as a result of new information, future developments or otherwise, except as may be required by law.

Contact:

STR Holdings, Inc.

Joseph C. Radziewicz

Controller and Principal Accounting Officer

+1 (860) 758-7325

joseph.radziewicz@strholdings.com

Or

ICR, LLC

Gary T. Dvorchak, CFA

Senior Vice President

Investor Relations Consultant

+1 (310) 954-1123

gary.dvorchak@icrinc.com

8

STR Holdings, Inc.

CONDENSED CONSOLIDATED INCOME STATEMENTS

All amounts in thousands except shares and per share amounts

9

STR Holdings, Inc.

CONDENSED CONSOLIDATED BALANCE SHEETS

All amounts in thousands

10

STR Holdings, Inc.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

All amounts in thousands

* Please refer to the reconciliation of Non-GAAP measures included in this press release.

11

STR Holdings, Inc.

RECONCILIATION OF NON-GAAP MEASURES

All amounts in thousands except shares and per share amounts

(1) Please refer to the reconciliation of diluted shares outstanding for non-GAAP net earnings per share included in this press release.

Non-GAAP Financial Measures

To supplement the Company’s condensed consolidated financial statements, which statements are prepared and presented in accordance with generally accepted accounting principles in the United States of America (GAAP), the Company uses non-GAAP financial measures to facilitate better understanding of its operating results. In this press release, there are two non-GAAP financial metrics mentioned: Non-GAAP earnings per share from continuing operations (EPS) and free cash flow as defined below:

Non-GAAP EPS: The Company believes that non-GAAP EPS from continuing operations provides meaningful supplemental information regarding its performance by excluding certain expenses that may not be indicative of the core business operating results and may help in comparing current period results with those of prior periods as well as with its peers. Non-GAAP EPS from continuing operations is defined as net earnings from continuing operations not including the tax effected impact of amortization of intangibles, deferred financing costs, stock-based compensation, intangible asset amortization expense, secondary offering expense, plant closure costs, asset impairment, goodwill impairment, plus interest expense from prior credit

12

facilities divided by the weighted-average common shares outstanding. Although the Company uses non-GAAP EPS from continuing operations as a measure to assess the operating performance of its business, non-GAAP EPS from continuing operations has significant limitations as an analytical tool because it excludes certain material costs. Because non-GAAP EPS from continuing operations does not account for these expenses, its utility as a measure of its operating performance has material limitations. Because of these limitations, the Company does not view non-GAAP EPS from continuing operations in isolation and uses other metrics to measure operating performance such as, but not limited to, net sales, gross margin, operating income, adjusted EBITDA, and net earnings from continuing operations.

During the current period, the Company has also included plant closure costs, goodwill impairment, asset impairment and interest expense from prior credit facilities as non-GAAP adjustments. Information regarding these items is set forth below:

·                  Plant closure costs:  The plant closure costs relate to the Company’s exit from its Florida manufacturing facility. The costs include severance associated with terminated employees, accelerated depreciation of abandoned machinery and equipment and other costs to exit the facility. The Company believes that the costs associated with the exit of its Florida facility will not recur after 2011 and is not indicative of its future operating results.

·                  Goodwill impairment:  In December 2011, the Company recorded a goodwill impairment of $63.9 million attributable to the decline in solar market conditions and the market capitalization of its common stock. The Company is excluding this item because it believes it is not reflective of the operational conditions of its core business, it is non-cash, and may be helpful in comparing its results with those of prior periods and as well as with its peers.

·                  Asset Impairment:  The non-cash asset impairment relates to the Company’s real property that used to be occupied by the QA business that was sold to UL on September 1, 2011.  Since this asset was not included as part of the sale transaction, the real property is now a non-operating asset of the Company which is being leased to UL under a one-year agreement.  As such, the Company has impaired this asset to reflect the sale and rental proceeds expected to be received.

·                  Interest expense from prior credit facilities:  The interest expense on the Company’s prior First and Second Lien debt was not directly related to the QA business. However, since the former credit facilities required the proceeds received from the UL transaction to be used to retire the First and Second Lien debt, GAAP requires the Company to record historical interest expense in discontinued operations.  However, the Company has recently closed on a new $150 million credit facility and may incur interest expense in the future. Since the interest expense related to both of its businesses from an operational standpoint, the Company is reducing the non-GAAP EPS from continuing operations to appropriately reflect its historical interest cost as the Company may incur interest expense in the future.

Weighted-average common shares outstanding

STR Holdings, Inc.

RECONCILIATION OF NON-GAAP SHARES OUTSTANDING

Diluted GAAP shares outstanding: Due to a loss from continuing operations during the quarter and year ended December 31, 2011, the diluted weighted-average common shares outstanding for purposes of its diluted GAAP loss per share (EPS) does not include 4,489 of stock options, 167,542 of restricted common stock, 543,088 of stock options and 397,641 of restricted common stock, respectively, as these potential awards do not share in any loss generated by the Company and are anti-dilutive.

Diluted non-GAAP shares outstanding: Due to a non-GAAP net loss from continuing operations during the quarter ended December 31, 2011, the weighted-average common shares outstanding for the purposes of its non-GAAP EPS does not include 4,489 of stock options and 167,542 of restricted common stock as these potential awards do not share in any loss generated by the Company and are anti-dilutive.

13

Free Cash Flow: The Company believes free cash flow is an important measure of its overall liquidity and its ability to fund future growth and provide a return to shareowners. Free cash flow is defined as cash flow from operations from continuing operations excluding cash spent on capital expenditures. A limitation of using free cash flow versus the GAAP measure of cash provided by operating activities as a means for evaluating the Company’s business is that free cash flow does not represent the total increase or decrease in the cash balance from operations for the period because it excludes cash used for capital expenditures during the period.

14