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                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION
                                       OF
                          NEXTLINK COMMUNICATIONS, INC.


         NEXTLINK COMMUNICATIONS, INC., a corporation organized and existing
under and by virtue of the General Corporation Law of the State of Delaware (the
"Corporation"), hereby certifies:

         FIRST: That the Board of Directors, by a unanimous written consent
dated July 14, 1999, resolutions were duly adopted by the Board of Directors
of the Corporation setting forth a proposed amendment to the Certificate of
Incorporation of the Corporation, declaring said amendment to be advisable
and directing that the proposed amendment and the matter thereof be
considered at the Annual Meeting of Stockholders of the Corporation held on
August 25, 1999. The resolution setting forth the proposed amendment is as
follows:

         WHERAS, the Company has determined to split its Class A and Class B
Common Stock on a two-for-one basis, to be effected in the form of a 100%
stock dividend, payable to stockholders of record on August 18, 1999, with a
payment date of August 27, 1999;

         WHEREAS, as a condition to effecting the stock split, and to provide
the Company with flexibility to conduct financings, other stock splits and
stock dividends, and acquisitions, the Company has determined to amend the
first paragraph of Article 3 of its Certificate of Incorporation to increase
the number of authorized shares of common stock (with the authorized shares
of preferred stock remaining at 25,000,000), which such paragraph, as
amended, shall read as follows:

                  The Corporation shall have authority to issue Four Hundred
         Sixty Million (460,000,000) shares of common stock (the "Common
         Stock"), which shall be divided into two classes, Four Hundred Million
         (400,000,000) shares of Class A Common Stock, par value $0.02 per share
         (the "Class A Common Stock"), and Sixty Million (60,000,000) shares of
         Class B Common Stock, par value $0.02 per share (the "Class B Common
         Stock"). The Corporation shall have authority to issue Twenty-Five
         Million (25,000,000) shares of preferred stock, par value $.01 per
         share (the "Preferred Stock").

         NOW, THEREFORE IT IS HEREBY RESOLVED, that the Board hereby
ratifies, approves, declares advisable, the stock split, as described above,
and the above-referenced amendment, subject to the proposed amendment
receiving the affirmative vote of a majority of the votes entitled to be cast
by holders of (i) Class A common stock, voting separately as a class, (ii)
Class B common stock, voting separately as a class, and (iii) both classes of
common stock, voting together as a single class, as required by the Delaware
General Corporation Law; and

         FURTHER RESOLVED, the Board hereby recommends that above-referenced
amendment be submitted to the stockholders for approval at the annual
meeting, and that the officers of the Company take such appropriate action,
including the preparation of a proxy and proxy statement, as is necessary to
carry out such resolution.

         SECOND: That thereafter, pursuant to resolutions of the Board of
Directors of the Corporation, the Annual Meeting of Stockholders of the
Corporation was duly called and held on August 25, 1999, upon notice in
accordance with Section 222 of the General Corporation Law of the State of
Delaware, at which meeting the necessary number of shares as required by
statute was voted in favor of the amendment.

         THIRD: That said amendment was duly adopted in accordance with the
provisions of Section 242 of the General Corporation Law of the State of
Delaware.

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         IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
signed by R. Bruce Easter, Jr., its Vice President, General Counsel and
Secretary, this 25th day of August, 1999.


                                   NEXTLINK COMMUNICATIONS, INC.


                                   By:     /s/ R. Bruce Easter, Jr.
                                      ----------------------------------------
                                   Name:   R. Bruce Easter, Jr.
                                   Title:  Vice President, General Counsel and
                                           Secretary