EXHIBIT 5.1

Cooley Godward LLP                    [LETTERHEAD]



February 1, 2001


Wireless Facilities, Inc.
4810 Eastgate Mall
San Diego, CA 92121

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by Wireless Facilities, Inc., a Delaware corporation (the
"Company") of a Registration Statement on Form S-8 (the "Registration
Statement") with the Securities and Exchange Commission, covering the offering
of up to 7,113,864 shares of the Company's Common Stock, $.001 par value (the
"Shares"), for issuance, including (i) 3,000,000 shares issuable pursuant to the
2000 Nonstatutory Stock Option Plan, (ii) 1,905,013 shares issuable under the
1999 Equity Incentive Plan pursuant to the automatic increase to the share
reserve that occurred on January 1, 2000 and (iii) 2,208,851 shares issuable
under the 1999 Equity Incentive Plan pursuant to the automatic increase on
January 1, 2001.

In connection with this opinion, we have examined and relied upon the
Registration Statement and related prospectus, the 2000 Nonstatutory Stock
Option Plan and the 1999 Equity Incentive Plan, the Company's Certificate of
Incorporation and Bylaws, as amended, 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, the conformity to
originals of all documents submitted to us as copies thereof and the due
execution and delivery of all documents where due execution and delivery are a
prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Shares, when issued and sold in accordance with the 2000 Nonstatutory
Stock Option Plan or the 1999 Equity Incentive Plan, as applicable, the
Registration Statement and related prospectus, will be validly issued, fully
paid and nonassessable (except as to shares issued pursuant to any deferred
payment arrangements, which will be fully paid and nonassessable when such
deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

Cooley Godward LLP

/s/ Lance W. Bridges
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Lance W. Bridges