UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K/A

(Amendment No. 1)

(Mark One)

For the fiscal year ended December 31, 2012

OR

For the transition period from_______to_______

Commission file number 001-33449

TOWERSTREAM CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (401) 848-5848

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o No x 

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes o No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No o 

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

Yes x No ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§ 229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes o No x

The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold as of the last business day of the registrant’s most recently completed second fiscal quarter was $206,417,846.

As of March 14, 2013, there were 66,355,741 shares of common stock, par value $0.001 per share, outstanding.

EXPLANATORY NOTE

We are filing this Amendment No. 1 on Form 10-K/A to our Annual Report on Form 10-K for the fiscal year ended December 31, 2012, as originally filed with the Securities and Exchange Commission (the “SEC”) on March 18, 2013 (the “Original Filing”), for the sole purpose of including the Company’s independent registered public accounting firm’s consent in the exhibit listing included in Part IV.

This Amendment No. 1 does not change any of the information contained in the Original Filing. Other than as specifically set forth herein, this Amendment No. 1 continues to speak as of the date of the Original Filing and we have not updated or amended the disclosures contained therein to reflect events that have occurred since the date of the Original Filing. Accordingly, this Amendment No. 1 should be read in conjunction with our filings made with the SEC subsequent to the date of the Original Filing.

PART IV

Item 15. Exhibits and Financial Statement Schedules.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

In accordance with the Exchange Act, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.