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) December 16, 2011

LIGHTING SCIENCE GROUP CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (321) 779-5520

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):

Section 3 – Securities and Trading Markets

Item 3.02 Unregistered Sales of Equity Securities.

On December 16, 2011, Lighting Science Group Corporation (the “Company”) issued 6,500 units (the “Series G Units”) of the Company’s securities to LSGC Holdings II LLC (“Holdings II”) at a price per Series G Unit of $1,000.00 and total consideration of $6,500,000. Each Series G Unit consists of: (i) one share of the Company’s Series G Preferred Stock (the “Series G Preferred Stock”) and (ii) 83 shares of the Company’s common stock, par value $0.001 per share (the “Common Stock”). The Company issued the Series G Units pursuant to an option to purchase Series G Units granted to Holdings II in connection with that certain Series G Unit Subscription Agreement (the “Series G Subscription Agreement”), dated as of December 1, 2011, by and among the Company, Holdings II, PCA LSG Holdings, LLC (“PCA”), Pegasus Partners IV, L.P. (“Pegasus IV”), Ensemble Lights, LLC, Belfer Investment Partners L.P., Lime Partners, LLC, Mr. Mark Kristoff and Mr. Alan Docter.

Through December 16, 2011, the Company has issued 32,108 Series G Units and raised an aggregate of approximately $32.1 million pursuant to the Series G Subscription Agreement and that certain Subscription Agreement (the “Series F Subscription Agreement”), dated as of November 17, 2011, by and among the Company, PCA and Pegasus IV.

The Company issued the shares of Series G Preferred Stock and Common Stock to Holdings II pursuant to the exemption from registration provided by Section 4(2) of the Securities Act of 1933, as amended, and the safe harbors for sales provided by Regulation D promulgated thereunder.

The foregoing description of the Series G Subscription Agreement and Series F Subscription Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Series G Subscription Agreement, which was filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed on December 6, 2011, and the Series F Subscription Agreement, which was filed as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed on November 21, 2011, each of which is incorporated herein by reference.

Holdings II and PCA are affiliates of Pegasus IV who, together with its affiliates, is the Company’s largest stockholder and beneficially owned approximately 84% of the Company’s Common Stock as of December 16, 2011 (calculated in accordance with Rule 13d-3 of the Securities Exchange Act of 1934, as amended).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.