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):

June 5, 2012

American Superconductor Corporation

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (978) 842-3000

Not Applicable

(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):

Item 1.01. Entry into a Material Definitive Agreement

On June 5, 2012 (the “Effective Date”), American Superconductor Corporation (the “Company”) and Hercules Technology Growth Capital, Inc. (the “Lender”) entered into a Loan and Security Agreement (the “Agreement”), providing the Company with a term loan in an aggregate principal amount of $10,000,000, which was fully drawn on the Effective Date (the “Term Loan”). The Term Loan is to be used for general corporate purposes.

The principal balance of the Term Loan bears interest at a floating per annum rate equal to 11% plus the percentage, if any, by which the prime rate exceeds 3.75%. The Company will make interest-only payments on the Term Loan beginning July 1, 2012 and continuing through November 1, 2012, after which the Company will repay the aggregate principal outstanding balance of the Term Loan in 26 equal monthly installments of principal, plus accrued interest at the applicable rate. The Term Loan matures on December 1, 2014.

Amounts outstanding under the Agreement are secured by substantially all of the Company’s existing and future assets (excluding certain customary items, but including the Company’s intellectual property). In order to further secure all of the Company’s obligations to Lender under the Agreement, the Company’s wholly-owned subsidiary, ASC Devens LLC (“ASC”), will also be entering into a mortgage with respect to the property it has rights to located at 64 Jackson Road, Devens, Massachusetts 01434-4020. The Agreement requires the Company to maintain a balance of unrestricted cash or cash equivalents equal to the principal amount of the Term Loan outstanding at such time in accounts that are subject to a control agreement with Lender.

The Agreement also contains covenants that restrict the Company’s ability to, among other things, incur or assume certain debt, merge or consolidate, materially change the nature of its business, make certain investments, acquire or dispose of certain assets, make guaranties or grant liens on its assets, make certain loans, advances or investments, declare dividends or make distributions or enter into transactions with affiliates. The events of default under the Agreement include, but are not limited to, failure to pay amounts due, breaches of covenants, bankruptcy events, cross defaults under other material indebtedness and the occurrence of a material adverse effect and/or change in control. In the case of a continuing event of default, the Lender may, among other remedies, declare due all unpaid principal amounts outstanding and any accrued but unpaid interest and foreclose on all collateral granted to the Lender as security under the Agreement. Two of the Company’s subsidiaries, ASC and Superconductivity, Inc., signed joinder agreements to the Agreement, whereby they agreed to be bound by certain terms and conditions as borrowers under the Agreement.

In connection with the Agreement, the Company issued a warrant (the “Warrant”) to the Lender to purchase 139,276 shares of the Company’s common stock with an exercise price of $3.59 per share, subject to price-based anti-dilution and other adjustments as set forth in the Warrant. The Warrant is immediately exercisable and expires on December 5, 2017. The Company issued the Warrant in reliance on the exemption from registration provided by Section 4(2) of the Securities Act of 1933.

Item 2.02. Results of Operations and Financial Condition.

On June 6, 2012, the Company announced its financial results for the fourth quarter and fiscal year ended March 31, 2012 (“fiscal 2011”). The full text of the press release issued in connection with the announcement is attached as Exhibit 99.1 to this Current Report on Form 8-K.

The information in this Item 2.02 of this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (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 or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth in Item 1.01 in connection with the Agreement is incorporated in this Item 2.03 by reference.

Item 3.02. Unregistered Sales of Equity Securities.

The information set forth in Item 1.01 in connection with the Warrant is incorporated in this Item 3.02 by reference.

2

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On June 5, 2012, the Compensation Committee of the Company (or, in the case of the Chief Executive Officer, the Board of Directors), based on the established goals under the Company’s executive incentive plan for fiscal 2011, approved the award of cash bonuses for Daniel P. McGahn, David A. Henry, Timothy D. Poor and Susan J. DiCecco (the “Executive Officers”) as set forth in the table below under the heading “Non-Equity Incentive Plan Compensation.” Other compensation for fiscal 2011 was previously reported by the Company in the Summary Compensation Table beginning on page 14 of the Company’s Form S-1 filed with the Securities and Exchange Commission on April 13, 2012 (the “Form S-1”). As of the filing of the Form S-1, the fiscal 2011 cash bonuses for the Executive Officers had not been determined and, therefore, were omitted from the Summary Compensation Table included in the Form S-1. The total fiscal 2011 compensation for each Executive Officer reported in the Summary Compensation Table on page 14 of the Form S-1 has been recalculated to include the fiscal 2011 bonuses as follows:

Summary Compensation Table

The following table contains information with respect to the compensation for fiscal 2011 of our principal executive officer, our former principal executive officer, our principal financial officer, our other remaining two executive officers who were serving as executive officers on March 31, 2012 and two additional individuals who served as executive officers during part of fiscal 2011 for whom disclosure is required pursuant to SEC rules.

3

4

Item 9.01. Financial Statements and Exhibits

d) Exhibits:

5

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.

6

EXHIBIT INDEX

7