Exhibit 5.1

December 17, 2010

Gentlemen:

You have requested our opinion with respect to certain matters in connection with the offering by Converted Organics Inc., a Delaware corporation (the “Company”), of certain convertible notes in aggregate principal amount of $4,990,000 (the “Notes”), three warrants designated as “Series A Warrants,” “Series B Warrants,” and “Series C Warrants,” each to purchase certain shares of the Company’s common stock, par value $0.0001 (“Common Stock”) (the Series A Warrants, Series B Warrants, and Series C Warrants, collectively, the “Warrants”) (collectively, the Notes, Warrants, and Common Stock, the “Securities”), pursuant to a securities purchase agreement dated December 17, 2010 (the “Purchase Agreement”) and a Registration Statement on Form S-3 (Registration Statement No. 333-167970) (the  “Registration Statement”), filed with the Securities and Exchange Commission (the  “Commission”) under the Securities Act of 1933, as amended (the  “Act” ), the prospectus included within the Registration Statement (the “Base Prospectus”), and the supplemented form of prospectus relating to the Securities dated December 17, 2010 and filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations of the Act (the “Prospectus Supplement “). (The Base Prospectus and Prospectus Supplement are collectively referred to as the “Prospectus.”) All of the Securities to be sold by the Company as described in the Registration Statement and Prospectus.

In connection with this opinion letter, we have examined the Registration Statement, the Prospectus, the Purchase Agreement, the forms of Notes and Warrants, originals, or copies certified or otherwise identified to our satisfaction, of the Company’s certificate of incorporation and bylaws, and any amendments thereto, and such other documents, records and other instruments as we have deemed appropriate for purposes of the opinion set forth herein.

In our examination, we have assumed (a) the authenticity of original documents and the genuineness of all signatures, (b) the conformity to the originals of all documents submitted to us as copies or telecopies, and (c) the truth, accuracy and completeness of the information, representations and warranties contained in the records, documents, instruments and certificates we have reviewed.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that:

(i) The Notes and Warrants constitute legal, valid and binding obligations of the Company, enforceable against it in accordance with their terms, except (i) as limited by applicable bankruptcy, insolvency, reorganization, moratorium, and other laws of general application affecting enforcement of creditors’ rights generally, (ii) as limited by laws relating to the availability of specific performance, injunctive relief, or other equitable remedies, and (iii) to the extent indemnification provisions contained such documents, if any, may be limited by applicable federal or state law and consideration of public policy.

(ii) The shares of Common Stock issuable upon conversion of the Notes and exercise of the Warrants, as of the date hereof, have been duly and validly authorized and, to our knowledge, reserved for issuance upon conversion of the Notes and exercise of such Warrants, and such shares of Common Stock, when so issued upon conversion of the Notes and exercise of the Warrants and, with respect to the Warrants, upon delivery by the purchaser of the consideration for such shares, will be duly authorized, validly issued, fully paid and non-assessable.

This opinion is limited to the Federal law of the United States, and the applicable statutory provisions of General Corporation Law of the State of Delaware, including all applicable provisions of the Delaware Constitution. The Securities may be issued from time to time on a delayed or continuous basis, and our opinion is limited to the laws as in effect on the date hereof.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference made to this firm in the Registration Statement under the heading “Legal Matters.”

In giving such consent, we do not believe that we are “experts” within the meaning of such term used in the Securities Act or the rules and regulations of the Securities and Exchange Commission issued thereunder with respect to any part of the Registration Statement, including this opinion as an exhibit or otherwise. This opinion may be used only in connection with the offer and sale of the Securities while the Registration Statement is effective.

Very truly yours,

/s/ Cozen O’Connor