Exhibit 5.1

		425 MARKET STREET SAN FRANCISCO CALIFORNIA 94105-2482   TELEPHONE: 415.268.7000 FACSIMILE: 415.268.7522   WWW.MOFO.COM		MORRISON & FOERSTER LLP   BEIJING, BERLIN, BRUSSELS, DENVER, HONG KONG, LONDON, LOS ANGELES, NEW YORK, NORTHERN VIRGINIA, PALO ALTO, SACRAMENTO, SAN DIEGO, SAN FRANCISCO, SHANGHAI, SINGAPORE, TOKYO, WASHINGTON, D.C.

June 2, 2014

Marrone Bio Innovations, Inc.

2121 Second St. Suite A-107

Davis, CA 95618

Re: Registration Statement on Form S-1

Ladies and Gentlemen:

We are acting as counsel to Marrone Bio Innovations, Inc., a Delaware corporation (the “Company”), in connection with the registration of 4,600,000 shares of the Company’s Common Stock, par value $0.00001 per share (the “Common Stock”), pursuant to a Registration Statement on Form S-1, as amended (the “Registration Statement”), filed with the Securities and Exchange Commission under the Securities Act of 1933, as amended, covering the issuance and sale by the Company of 3,400,000 shares of Common Stock (the “Primary Shares”), the offering and sale by the selling stockholder identified in the Registration Statement of 600,000 shares of Common Stock (the “Secondary Shares”) and, if exercised, the sale by the Company of up to 600,000 shares of Common Stock subject to an option to purchase additional shares (the “Optional Shares” and, together with the Primary Shares and the Secondary Shares, the “Shares”).

As counsel for the Company, we have examined originals or copies, certified or otherwise identified to our satisfaction, of such documents, corporate records, certificates of public officials and other instruments as we have deemed necessary for the purposes of rendering this opinion and we are familiar with the proceedings taken and proposed to be taken by the Company in connection with the authorization, issuance and sale of the Shares. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals and the conformity with the originals of all documents submitted to us as copies.

Based upon the foregoing, we are of the opinion that:

Marrone Bio Innovations, Inc.

June 2, 2014

Page Two

We consent to the use of this opinion as an exhibit to the Registration Statement, and we consent to the reference of our name under the caption “Legal Matters” in the Prospectus forming a part of the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.