Exhibit 5.1

July 13, 2017

VIA ELECTRONIC MAIL

Trovagene, Inc.

11055 Flintkote Avenue

San Diego, CA 92121

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the offering for sale to certain underwriters (the “Underwriters”) of 6,191,500 shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) pursuant to the Registration Statement (as defined below) and the Prospectus (as defined below). Unless defined herein, capitalized terms have the meanings given to them in that certain Securities Purchase Agreement, dated July 13, 2017, by and among the Company and certain accredited investors identified on the signature pages thereto (the “Purchase Agreement”).

This opinion is being furnished in accordance with the requirements of Item 601(b)(5)(i) of Regulation S-K.

In connection with this opinion, we have reviewed and relied upon the following:

Trovagene, Inc.

July 13, 2017

Page 2

In our examination, we have assumed the genuineness of all signatures, including endorsements, the legal capacity and competency of all natural persons, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as facsimile, electronic, certified or photocopy, and the authenticity of the originals of such copies. As to any facts relevant to the opinions stated herein that we did not independently establish or verify, we have relied upon statements and representations of officers and other representatives of the Company and others and of public officials.

Based upon the foregoing and subject to the qualifications and assumptions stated herein, we are of the opinion that the shares of Common Stock have been duly authorized by all requisite corporate action on the part of the Company under the Delaware General Corporation Law (the “DGCL”) and, when the shares of Common Stock are delivered to and paid for by the Purchaser in accordance with the terms of the Purchase Agreement and when evidence of the issuance thereof is duly recorded in the Company’s books and records, the Shares will be validly issued, fully paid and non-assessable.

We hereby consent to the filing of this opinion letter as an exhibit to the Company’s Current Report on Form 8-K being filed on the date hereof and incorporated by reference into the Registration Statement. We also hereby consent to the reference to our firm under the caption “Legal Matters” in the Prospectus. In giving this consent, we do not admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, the rules and regulations of the Securities and Exchange Commission promulgated thereunder or Item 509 of Regulation S-K.

We express no opinion as to matters governed by any laws other than the DGCL.

This opinion letter is rendered to you solely for use in connection with the issuance and sale of the shares of Common Stock in accordance with the Registration Statement as of the date first written above and is not to be relied on for any other purpose. We disclaim any

Trovagene, Inc.

July 13, 2017

Page 3

obligation to advise you of facts, circumstances, events or developments that hereafter may be brought to our attention and that may alter, affect or modify the opinion expressed herein. Our opinion is expressly limited to the matters set forth above and we render no opinion, whether by implication or otherwise, as to any other matters relating to the Company or the shares of Common Stock.