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 15, 2011

Hercules Technology Growth Capital, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (650) 289-3060

Not Applicable

(Former name or 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 April 15, 2011, in connection with a previously announced private offering, Hercules Technology Growth Capital, Inc. (the “Company”) issued $75.0 million in aggregate principal amount of 6.00% Convertible Senior Notes due 2016 (the “Convertible Notes”) pursuant to an Indenture, dated April 15, 2011 (the “Indenture”), between the Company and U.S. Bank National Association, as trustee (the “Trustee”). The sale of the Convertible Notes generated net proceeds of approximately $72.0 million. Aggregate estimated offering expenses in connection with the transaction, including the initial purchaser’s discount of approximately $2.6 million, were approximately $3.0 million.

The Convertible Notes mature on April 15, 2016 (the “Maturity Date”), unless previously converted or repurchased in accordance with their terms. The Convertible Notes bear interest at a rate of 6.00% per year payable semiannually in arrears on April 15 and October 15 of each year, commencing on October 15, 2011. The Convertible Notes are the Company’s senior unsecured obligations and rank senior in right of payment to the Company’s existing and future indebtedness that is expressly subordinated in right of payment to the Convertible Notes; equal in right of payment to the Company’s existing and future unsecured indebtedness that is not so subordinated; effectively junior in right of payment to any of the Company’s secured indebtedness (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness; and structurally junior to all existing and future indebtedness (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

Prior to the close of business on the business day immediately preceding October 15, 2015, holders may convert their Convertible Notes only under certain circumstances set forth in the Indenture. On or after October 15, 2015 until the close of business on the scheduled trading day immediately preceding the Maturity Date, holders may convert their Convertible Notes at any time. Upon conversion, the Company will pay or deliver, as the case may be, at its election, cash, shares of its common stock or a combination of cash and shares of its common stock. The conversion rate will initially be 84.0972 shares of common stock per $1,000 principal amount of Convertible Notes (equivalent to an initial conversion price of approximately $11.89 per share of common stock). The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, if certain corporate events occur prior to the Maturity Date, the conversion rate will be increased for converting holders.

The Company may not redeem the Convertible Notes prior to maturity. No sinking fund is provided for the Convertible Notes. In addition, if certain corporate events occur in respect of the Company, holders of Convertible Notes may require the Company to repurchase for cash all or part of their Convertible Notes at a repurchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid interest through, but excluding, the required repurchase date.

The Indenture contains certain covenants, including a covenant to provide financial information to the holders of the Convertible Notes and the Trustee if the Company ceases to be subject to the reporting requirements of the Securities Exchange Act of 1934, as amended. These covenants are subject to important limitations and exceptions that are described in the Indenture.

The Company offered and sold the Convertible Notes to the initial purchaser in reliance on the exemption from registration provided by Section 4(2) of the Securities Act of 1933, as amended (the “Securities Act”), for resale by the initial purchaser to qualified institutional buyers (as defined in the Securities Act) pursuant to the exemption from registration provided by Rule 144A under the Securities Act. The Company relied on these exemptions from registration based in part on representations made by the initial purchaser in the purchase agreement executed in connection with the sale of the Convertible Notes.

The foregoing description of the Indenture and the Convertible Notes does not purport to be complete and is qualified in its entirety by reference to the full text of the Indenture (including the Form of the 6.00% Convertible Notes due 2016), filed as an exhibit hereto and incorporated by reference herein.

Neither the Convertible Notes nor the common stock that may be issued upon conversion thereof will be registered under the Securities Act. Neither the Convertible Notes nor the common stock that may be issued upon conversion thereof may be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act. This Current Report on Form 8-K does not constitute an offer to sell, or a solicitation of an offer to buy, any security and shall not constitute an offer, solicitation or sale in any jurisdiction in which such offer, solicitation or sale would be unlawful.

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 under Item 1.01 of this Form 8-K is incorporated herein by reference.

Item 3.02 Unregistered Sales of Equity Securities.

The information set forth under Item 1.01 of this Form 8-K is incorporated herein by reference.

Item 8.01 Other Events.

On April 18, 2011, the Company issued a press release announcing the closing of the private offering of the Convertible Notes.

Item 9.01 Financial Statements and Exhibits.

(d) 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.