Exhibit 5.1

               [Letterhead of Cadwalader, Wickershan & Taft LLP]

February 27, 2007

Frequency Electronics, Inc.
55 Charles Lindbergh Blvd.
Mitchel Field, NY 11553

Re: Registration Statement on Form S-8

Ladies and Gentlemen:

      We have acted as special counsel to Frequency Electronics, Inc., a
Delaware corporation (the "Company") in connection with the preparation and
filing by the Company with the Securities and Exchange Commission (the
"Commission") of a Registration Statement on Form S-8 (the "Registration
Statement") under the Securities Act of 1933, as amended (the "Securities Act").
The Registration Statement relates to the registration of up to 1,159,635 shares
of common stock, par value $1.00 per share, of the Company (the "Shares") to be
issued and sold under the 2001 Incentive Stock Option Plan, the 2005 Stock Award
Plan of Frequency Electronics, Inc. and the Frequency Electronics, Inc. Employee
Stock Ownership Plan (collectively, the "Plans").

      In rendering the opinion set forth below, we have examined and relied upon
the originals, copies or specimens, certified or otherwise identified to our
satisfaction, of the Registration Statement, the Plans and such certificates,
corporate and public records, agreements and instruments and other documents,
including, among other things, the documents delivered on the date hereof, as we
have deemed appropriate as a basis for the opinion expressed below. In such
examination we have assumed the genuineness of all signatures, the authenticity
of all documents, agreements and instruments submitted to us as originals, the
conformity to original documents, agreements and instruments of all documents,
agreements and instruments submitted to us as copies or specimens, the
authenticity of the originals of such documents, agreements and instruments
submitted to us as copies or specimens, the conformity of the text of each
document filed with the Commission through the Commission's Electronic Data
Gathering, Analysis and Retrieval System to the printed document reviewed by us,
and the accuracy of the matters set forth in the documents, agreements and
instruments we reviewed. As to matters of fact relevant to the opinion expressed
herein, we have relied upon, and assumed the accuracy of, the statements and
representations of officers and other representatives of the Company and we have
relied upon certificates and oral or written statements and other information
obtained from the Company and public officials. Except as expressly set forth
herein, we have not undertaken any independent investigation (including, without
limitation, conducting any review, search or investigation of any public files,
records or dockets) to determine the existence or absence of the facts that are
material to our opinion, and no inference as to our knowledge concerning such
facts should be drawn from our reliance on the representations of the Company
and others in connection with the preparation and delivery of this letter.

      We express no opinion concerning the laws of any jurisdiction other than
the laws of the State of New York and the General Corporation Law of the State
of Delaware. While we are not licensed to practice law in the State of Delaware,
we have reviewed applicable provisions of the Delaware General Corporation Law
as we have deemed appropriate in connection with the opinion expressed herein.
Except as described, we have neither examined nor do we express any opinion with
respect to Delaware law.

      Based upon and subject to the foregoing, we are of the opinion that the
Shares, when issued and delivered by the Company pursuant to the Plans, will be
validly issued, fully paid and non-assessable.

      We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In doing so, we do not admit that we are in the category
of persons whose consent is required under Section 7 of the Securities Act or
the rules and regulations of the Commission promulgated thereunder. Without our
prior written consent, this letter is not to be relied upon, used, circulated,
quoted or otherwise referred to by, or assigned to, any other person (including
any person that acquires any Shares from you or that seeks to assert your rights
in respect of this letter (other than your successor in interest by means of
merger, consolidation, transfer of a business or other similar transaction)) or
for any other purpose. In addition, we disclaim any obligation to update this
letter for changes in fact or law or otherwise.

Very truly yours,

/s/ Cadwalader, Wickersham & Taft LLP