EXHIBIT 5.1

[letterhead]

January 31, 2014

Network-1 Technologies, Inc.

445 Park Avenue, Suite 1020

New York, New York  10022

Re:  Network-1 Technologies, Inc.

Registration Statement on Form S-8         

We have acted as counsel for Network-1 Technologies, Inc., a Delaware corporation (the “Company”), in connection with the preparation and filing of a Registration Statement on Form S-8 (the “Registration Statement”) with the Securities and Exchange Commission (the “Commission”), with respect to the registration under the Securities Act of 1933, as amended (the “Act”), of 300,000 shares of the Company’s common stock, par value $.01 per share (the “Shares”), issuable upon exercise of an option granted to a director of the Company pursuant to an individual option agreement (the “Option Agreement”).

We have examined and relied upon originals, or copies certified or otherwise identified to our satisfaction, of such documents and corporate and public records as we deemed necessary as a basis for the opinion hereinafter expressed. We have not performed any independent investigation other than the document examination described. Our opinion is therefore qualified in all respects by the scope of that document examination. We have assumed and relied, as to questions of fact and mixed questions of law and fact, on the truth, completeness, authenticity and due authorization of all documents and records examined and the genuineness of all signatures appearing on all documents presented to us as originals, and the conformity to the originals of all documents presented to us as conformed or reproduced copies.

In rendering this opinion, we have assumed that (i) the Shares will be issued in accordance with the terms and conditions of the Option Agreement, (ii) at the time of issuance of any Shares, there shall be a sufficient number of duly authorized and unissued shares of the Company’s common stock to accommodate the issuance of the Shares, and (iii) the per share consideration received by the Company in exchange for the issuance of any Shares shall not be less than the par value per share of the Company’s common stock.

This opinion is limited to the laws of the State of Delaware. In rendering this opinion, we have assumed compliance with all other laws, including federal laws and state securities laws.

Based upon the foregoing, it is our opinion that the Shares, when sold, paid for and issued as contemplated by the Registration Statement and the terms of the Option Agreement, will be validly issued, fully paid and nonassessable.

This opinion is given as of the date hereof. We assume no obligation to update or supplement this opinion to reflect facts or circumstances that may hereafter come to our attention or any changes in laws that may hereafter occur.

This opinion is strictly limited to the matters stated herein and no other or more extensive opinion is intended, implied or to be inferred beyond the matters stated herein.

A partner of this firm owns 26,084 shares of common stock of the Company.

We hereby consent to the use of this opinion as Exhibit 5.1 to the Registration Statement and to the use of our name as your counsel in connection with the Registration Statement. In giving this consent, we do not thereby concede that we come within the categories of persons whose consent is required by the Act or the General Rules and Regulations promulgated thereunder.

 

Very truly yours,

/s/ Eiseman Levine Lehrhaupt & Kakoyiannis, P.C.

Eiseman Levine Lehrhaupt & Kakoyiannis, P.C.