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 21, 2012

ORGANOVO HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

6275 Nancy Ridge Dr.,

San Diego, California 92121

(Address of principal executive offices, including zip code)

(858) 550-9994

(Registrant’s telephone number, including area code)

(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):

On December 21, 2012 , Organovo Holdings, Inc. (the “Company”) consummated its offer (the “Warrant Tender Offer”) to amend certain of its outstanding warrants to purchase an aggregate of 14,510,928 shares of the Company’s common stock, including: (i) outstanding warrants to purchase 1,500,000 shares of the Company’s common stock issued to investors participating in the Company’s bridge financing completed in November 2011 (the “Bridge Warrants”); (ii) outstanding warrants to purchase 11,653,678 shares of the Company’s common stock issued to investors participating in the Company’s private placement financings closed on February 8, 2012, February 29, 2012 and March 16, 2012 (the “Investor Warrants”); and (iii) outstanding warrants to purchase 1,357,250 shares of the Company’s common stock issued to investors in the Company’s private placement transactions completed in 2011 (the “Private Warrants”, and collectively with the Bridge Warrants and the Investor Warrants, the “Original Warrants”).

The Warrant Tender Offer expired at 5:00 p.m. Pacific Time on December 21, 2012. Pursuant to the Warrant Tender Offer, an aggregate of 9,578,344 Original Warrants were tendered by their holders and were amended and exercised in connection therewith for an aggregate exercise price of approximately $7.7 million, including the following: 502,500 Bridge Warrants; 8,606,094 Investor Warrants; and 469,750 Private Warrants. Such tendered Original Warrants represent approximately 66.0% of the Company’s outstanding Original Warrants as of November 16, 2012.

Following the amendment and exercise of the 9,578,344 Original Warrants, the Company had 58,493,717 shares of common stock issued and outstanding, excluding outstanding options and warrants to purchase 2,762,253 and 11,064,779 shares of the Company’s common stock, respectively.

The Company issued the Original Warrants in private placement transactions in reliance on the exemption from registration provided by Rule 506 of Regulation D under the Securities Act of 1933, as amended (the “Securities Act”). In connection with such transactions, the holders of the Original Warrants represented that they were “accredited investors.” Similarly, the issuance of the shares of the Company’s common stock upon the amendment and exercise of the 9,578,344 Original Warrants was exempt from registration under the Securities Act pursuant to Rule 506 of Regulation D. In connection with the Warrant Tender Offer, the holders of the tendered warrants represented that they were “accredited investors.”

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.