March 15, 2013

Cardica, Inc.

900 Saginaw Drive

Redwood City, CA 94063

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the offering by Cardica, Inc., a Delaware corporation (the “Company”), of up to 14,251,368 shares (the “Shares”) of the Company’s common stock, par value $0.001 (the “Common Stock”), pursuant to a Registration Statement on Form S-3 (Registration No. 333-171197) (the “Registration Statement”), filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), the related prospectus dated February 7, 2011 (the “Base Prospectus”) and the prospectus supplement dated March 13, 2015, filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations (the “Prospectus Supplement”). (The Base Prospectus and the Prospectus Supplement are collectively referred to as the “Prospectus.”) The Shares are to be sold by the Company as described in the Registration Statement and the Prospectus.

In connection with this opinion, we have examined and relied upon the Registration Statement and the Prospectus, the Company’s Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws, each as currently in effect, and the originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness and authenticity of all documents submitted to us as originals, and the conformity to originals of all documents submitted to us as copies; the accuracy, completeness and authenticity of certificates of public officials, and the due execution and delivery of all documents where due execution and delivery are a prerequisite to the effectiveness thereof.

Our opinion is expressed only with respect to the federal laws of the United States of America and the General Corporation Law of the State of Delaware.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold in accordance with the Registration Statement and the Prospectus, will be validly issued, fully paid and nonassessable.

We consent to the reference to our firm under the caption “Legal Matters” in the Prospectus included in the Registration Statement and to the filing of this opinion as an exhibit to a current report of the Company on Form 8-K.

FIVE PALO ALTO SQUARE, 3000 EL CAMINO REAL, PALO ALTO, CA 94306-2155 T: (650) 843-5000 F: (650) 849-7400 WWW.COOLEY.COM

Very truly yours,

Cooley llp

FIVE PALO ALTO SQUARE, 3000 EL CAMINO REAL, PALO ALTO, CA 94306-2155 T: (650) 843-5000 F: (650) 849-7400 WWW.COOLEY.COM