As filed with the Securities and Exchange Commission on August 11, 2014

Securities Act File No. 333-187447

U.S. SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-2

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

(Check appropriate box or boxes)

Pre-Effective Amendment No.     

Post-Effective Amendment No. 6

HERCULES TECHNOLOGY GROWTH CAPITAL, INC.

(Exact name of Registrant as specified in charter)

400 Hamilton Avenue, Suite 310

Palo Alto, CA 94301

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (650) 289-3060

Manuel A. Henriquez

Chief Executive Officer

Hercules Technology Growth Capital, Inc.

400 Hamilton Avenue, Suite 310

Palo Alto, CA 94301

(Name and address of agent for service)

COPIES TO:

Cynthia M. Krus

Lisa A. Morgan

Sutherland Asbill & Brennan LLP

700 Sixth Street, N.W., Suite 700

Washington, DC 20001

APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:

As soon as practicable after the effective date of this Registration Statement.

If any securities being registered on this form will be offered on a delayed or continuous basis in reliance on Rule 415 under the Securities Act of 1933, other than securities offered in connection with a dividend reinvestment plan, check the following box. x

It is proposed that this filing will become effective (check appropriate box): x when declared effective pursuant to section 8(c).

EXPLANATORY NOTE

This Post-Effective Amendment No. 6 to the Registration Statement on Form N-2 (File No. 333-187447) of Hercules Technology Growth Capital, Inc. (the “Registration Statement”) is being filed pursuant to Rule 462(d) under the Securities Act of 1933, as amended (the “Securities Act”), solely for the purpose of filing exhibits to the Registration Statement. Accordingly, this Post-Effective Amendment No. 6 consists only of a facing page, this explanatory note and Part C of the Registration Statement on Form N-2 setting forth the exhibits to the Registration Statement. This Post-Effective Amendment No. 6 does not modify any other part of the Registration Statement. Pursuant to Rule 462(d) under the Securities Act, this Post-Effective Amendment No. 6 shall become effective immediately upon filing with the Securities and Exchange Commission. The contents of the Registration Statement are hereby incorporated by reference.

PART C—OTHER INFORMATION

Item 25. Financial Statements and Exhibits

1. Financial Statements

The following financial statements of Hercules Technology Growth Capital, Inc. (the “Company” or the “Registrant”) are included in this registration statement in “Part A—Information Required in a Prospectus”:

2. Exhibits

Item 26. Marketing Arrangements

The information contained under the heading “Plan of Distribution” of the prospectus is incorporated herein by reference, and any information concerning any underwriters will be contained in any prospectus supplement if any, accompanying this prospectus.

Item 27. Other Expenses of Issuance and Distribution

The following table sets forth the estimated expenses payable by us in connection with the offering (excluding placement fees):

Item 28. Persons Controlled by or Under Common Control

Hercules Technology SBIC Management, LLC is a wholly owned subsidiary of the Company. Hercules Technology SBIC Management, LLC is the general partner of Hercules Technology II, L.P., Hercules Technology III, LP and Hercules Technology IV, LP and the Company owns substantially all of the limited partnership interests in Hercules Technology II, L.P. Hercules Technology III, L.P. and Hercules Funding II LLC, Hercules Technology Management Co. II, Inc., Hercules Technology Management Co. III, Inc., Hercules Technology Management Co. V, Inc., Hercules Technology I, LLC, Hercules Technology II, LLC, Hydra Ventures LLC, and Hercules Capital Funding Trust 2012-1 and Hercules Capital Funding 2012-1 LLC are wholly owned subsidiaries of the Company. Accordingly, the Company may be deemed to control, directly or indirectly, the following entities:

Item 29. Number of Holder of Securities

The following table sets forth the approximate number of shareholders of the Company’s common stock as of May 6, 2014:

Item 30. Indemnification

Maryland law permits a Maryland corporation to include in its charter a provision limiting the liability of its directors and officers to the corporation and its stockholders for money damages except for liability resulting from (a) actual receipt of an improper benefit or profit in money, property or services or (b) active and deliberate dishonesty established by a final judgment as being material to the cause of action. The Registrant’s charter contains such a provision which eliminates directors’ and officers’ liability to the maximum extent permitted by Maryland law, subject to the requirements of the 1940 Act.

The Registrant’s charter authorizes the Registrant, to the maximum extent permitted by Maryland law and subject to the requirements of the 1940 Act, to obligate itself to indemnify any present or former director or officer or any individual who, while a director or officer of the Registrant and at its request, serves or has served another corporation, real estate investment trust, partnership, joint venture, trust, employee benefit plan or other enterprise as a director, officer, partner or trustee, from and against any claim or liability to which that person may become subject or which that person may incur by reason of his or her service in any such capacity and, under certain circumstances and provided certain conditions have been met, to pay or reimburse their reasonable expenses in advance of final disposition of a proceeding. The Registrant’s bylaws obligate the Registrant, to the maximum extent permitted by Maryland law and subject to the requirements of the 1940 Act, to indemnify any present or former director or officer or any individual who, while a director or officer of the Registrant and at its request, serves or has served another corporation, real estate investment trust, partnership, joint venture, trust, employee benefit plan or other enterprise as a director, officer, partner or trustee and who is made, or threatened to be made, a party to the proceeding by reason of his or her service in any such capacity from and against any claim or liability to which that person may become subject or which that person may incur by reason of his or her service in any such capacity and, under certain circumstances and provided certain conditions have been met, to pay or reimburse their reasonable expenses in advance of final disposition of a proceeding. The charter and bylaws also permit the Registrant to indemnify and, under certain circumstances and provided certain conditions have been met, advance expenses to any person who served a predecessor of the Registrant in any of the capacities described above and any of the Registrant’s employees or agents or any employees or agents of its predecessor. In accordance with the 1940 Act, the Registrant will not indemnify any person for any liability to which such person would be subject by reason of such person’s willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of his office. Additionally, the Registrant will not indemnify any person with respect to any matter as to which such person shall have been finally adjudicated in any proceeding not to have acted in good faith in the reasonable belief that their action was in the best interests of the Registrant.

Maryland law requires a corporation (unless its charter provides otherwise, which the Registrant’s charter does not) to indemnify a director or officer who has been successful, on the merits or otherwise, in the defense of any proceeding to which he or she is made, or threatened to be made, a party by reason of his or her service in that capacity. Maryland law permits a corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made, or threatened to be made, a party by reason of their service in those or other capacities unless it is established that (a) the act or omission of the director or officer was material to the matter giving rise to the proceeding and (1) was committed in bad faith or (2) was the result of active and deliberate dishonesty, (b) the director or officer actually received an improper personal benefit in money, property or services or (c) in the case of any criminal proceeding, the director or officer had reasonable cause to believe that the act or omission was unlawful. However, under Maryland law, a Maryland corporation may not indemnify for an adverse judgment in a suit by or in the right of the corporation or for a judgment of liability on the basis that a personal benefit was improperly received, unless in either case a court orders indemnification, and then

only for expenses. In addition, Maryland law permits a corporation to advance reasonable expenses to a director or officer upon the corporation’s receipt of (a) a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation and (b) a written undertaking by him or her or on his or her behalf to repay the amount paid or reimbursed by the corporation if it is ultimately determined that the standard of conduct was not met.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended, may be permitted to directors, officers and controlling persons of the Company pursuant to the provisions described above, or otherwise, the Company has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Company of expenses incurred or paid by a director, officer or controlling person in the successful defense of an action, suit or proceeding) is asserted by a director, officer or controlling person in connection with the securities being registered, the Company will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

The Company carries liability insurance for the benefit of its directors and officers (other than with respect to claims resulting from the willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of his or her office) on a claims-made basis of up to $3,000,000, subject to a $250,000 retention and the other terms thereof.

The Company has agreed to indemnify the underwriters against specified liabilities for actions taken in their capacities as such, including liabilities under the Securities Act of 1933, as amended.

Item 31. Business and Other Connections of Investment Advisor

Not applicable.

Item 32. Location of Accounts and Records

The Company maintains at its principal office physical possession of each account, book or other document required to be maintained by Section 31(a) of the 1940 Act and the rules thereunder.

Item 33. Management Services

Not applicable.

Item 34. Undertakings

The Registrant undertakes:

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant has duly caused this Post-Effective Amendment No. 6 to the Registration Statement on Form N-2 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Palo Alto, and State of California, on the 11^th day of August, 2014.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.