Willkie Farr & Gallagher
                               787 Seventh Avenue
                             New York, NY 10019-6099



August 26, 1999

NEXTLINK Communications, Inc.
500 108th Avenue N.E., Suite 2200
Bellevue, Washington  98004

Ladies and Gentlemen:

We have acted as counsel to NEXTLINK Communications, Inc. (the "Company"), a
corporation organized under the laws of the State of Delaware, with respect to
the Company's Form S-8 Registration Statement (the "Registration Statement") to
be filed by the Company with the Securities and Exchange Commission on or about
August 26, 1999 in connection with the registration under the Securities Act of
1933, as amended, by the Company of an aggregate of 8,145,304 shares of Class A
common stock, par value $0.02 per share (the "Common Stock"), issuable pursuant
to the terms of the NEXTLINK Communications, Inc. Stock Option Plan (the
"Plan").

As counsel for the Company, we have examined, among other things, such Federal
and state laws and originals and/or copies (certified or otherwise identified to
our satisfaction) of such documents, certificates and records as we deemed
necessary and appropriate for the purpose of preparing this opinion.

Based on the foregoing, we hereby inform you that, in our opinion, the shares of
Common Stock to be originally issued have been duly and validly authorized for
issuance and, when issued in accordance with the terms of the Plan for
consideration in excess of $0.02 per share, will be validly issued, fully paid,
and nonassessable.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.  In giving such consent, we do not hereby admit that we
come within the category of persons whose consent is required under Section 7 of
the Act or the rules and regulations of the Securities and Exchange Commission.

This opinion is limited to the laws of the State of New York, the General
Corporation Law of the State of Delaware and Federal law.

Very truly yours,

/s/ Willkie Farr & Gallagher