<PAGE>
 
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON APRIL 15, 1998.
                                                           REGISTRATION NO. 333-
================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, DC 20549

                                   FORM S-8
                                        
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                         ADVANCED RADIO TELECOM CORP.
            (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<CAPTION> 
        DELAWARE                             4812                      52-1869023
<S>                               <C>                               <C>
(STATE OR OTHER JURISDICTION      (PRIMARY STANDARD INDUSTRIAL      (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION)      CLASSIFICATION CODE NUMBER)     IDENTIFICATION NO.)
</TABLE>

  500 108TH AVENUE NE, SUITE 2600, BELLEVUE, WASHINGTON 98004  (425) 688-8700
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                            THOMAS M. WALKER, ESQ.
                                GENERAL COUNSEL
                        500 108TH AVENUE NE, SUITE 2600
                          BELLEVUE, WASHINGTON  98004
                     (425) 688-8700 / (425) 990-1642 (FAX)
(NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)

                       COPIES OF ALL COMMUNICATIONS TO:

                              MARY E. WEBER, ESQ.
                                 ROPES & GRAY
                            ONE INTERNATIONAL PLACE
                            BOSTON, MA  02110-2624
                     (617) 951-7000 / (617) 951-7050 (FAX)
                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
==================================================================================================================================
   Title of Securities      Amount to be         Proposed maximum               Proposed maximum               Amount of
     to be registered        registered      offering price per share/(1)/  aggregate offering price/(1)/  registration fee/(2)/
----------------------------------------------------------------------------------------------------------------------------------
<S>                         <C>              <C>                            <C>                            <C>
   Common Stock, par         3,100,000              $14.6563                        $45,434,530                 $13,403.19
 value, $.001 (including
 Junior Preferred Stock
   Purchase Rights)
==================================================================================================================================
</TABLE>

(1)  Estimated solely for the purpose of determining the registration fee
     pursuant to Rule 457(c) for the purpose of calculating the registration fee
     based on the average of the high and low prices of the Registrant's Common
     Stock reported on the Nasdaq National Market on April 13, 1998.
(2)  An additional filing fee of $4,598.01 was previously paid for 1,475,000
     shares registered for issuance under the Restated Equity Incentive Plan and
     the 1996 Non-Employee Directors Automatic Stock Option Plan under
     Registration Statement 333-21875. Of the $4,598.01, $4,364.08 represents
     the filing fee for the 1,400,000 shares registered for issuance under the
     Restated Equity Incentive Plan and $233.93 represents the filing fee for
     the 75,000 shares registered for issuance under the 1996 Non-Employee
     Directors Automatic Stock Option Plan.

     Pursuant to Rule 429 under the Securities Act of 1933, the Prospectus
included herein also relates to a total of 1,400,000 shares of the Registrant
that are registered under Registration Statement on Form S-8 No. 333-21875,
which was filed on February 14, 1997.  This Registration Statement constitutes
Post-Effective Amendment No. 1 to Registration Statement on Form S-8 No. 333-
21875 pursuant to which any outstanding shares previously registered under
Registration Statement on Form S-8 No. 333-21875 may be offered and sold,
together with the securities registered hereunder, through the use of the
combined Prospectus included herein.  In the event any of such previously
registered shares are offered and sold prior to the effective date of this
Registration Statement, the amount of such shares will not be included in any
Prospectus hereunder.
================================================================================
<PAGE>
 
                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference.
          --------------------------------------- 

          The Registrant hereby incorporates the following documents herein by
reference:

          1)   The Company's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1997.
     
          2)   The Company's Current Report on Form 8-K filed with the
               Commission on March 5, 1998.

          3)   The description of the Company's Common Stock and Junior
               Preferred Stock Purchase Rights contained in the Company's
               Registration Statements on Forms 8-A and 8-A/A (File No. 000-
               21091) filed under Section 12 of the Securities Exchange Act of
               1934, as amended (the "Exchange Act").

          All other documents subsequently filed by the Company pursuant to
Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold, shall be deemed
to be incorporated by reference in this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained herein
or in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein or in any subsequently
filed document that also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

          The Registrant will provide without charge to each participant those
documents containing information regarding the respective Plans required by Item
1 of the Form S-8 as specified by Rule 428(b). The Registrant will also provide
without charge, upon the oral or written request of any particpant, a copy of
any and all documents that have been incorporated by reference in Item 3 of Part
II of this Registration Statement. Such documents may be obtained by writing to
Advanced Radio Telecom Corp., 500 108th Avenue, N.E., Suite 2600, Bellevue,
Washington 98004 or by calling (425) 688-8700. In accordance with Rule 428 and
the requirements of Part I of Form S-8, the Plans and any documents incorporated
by reference are not being filed with the Securities and Exchange Commission
("Commission") either as part of this Registration Statement or as prospectuses
or prospectus supplements pursuant to Rule 424. Upon request, the Registrant
shall furnish to the Commission or its staff a copy of copies of all of the
above-referenced documents.

Item 4 .  Description of Securities.
          ------------------------- 

          Not required.

Item 5.   Interests of Named Experts and Counsel.
          -------------------------------------- 

          Not required.

Item 6.   Indemnification of Directors and Officers.
          ----------------------------------------- 

          Section 145 of the Delaware General Corporation Law, as amended (the
"DGCL"), provides that a corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal or investigative
(other than an action by or in the right of the corporation) by reason of the
fact that he is or was a director, officer, employee or agent of the
corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another 
<PAGE>
 
corporation, partnership, joint venture, trust or other enterprise, against
expenses (including attorneys' fees), judgments, fines and amount paid in
settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
corporation, and, with respect to any criminal action or proceeding, had not
reasonable cause to believe his conduct was unlawful. Section 145 further
provides that a corporation similarly may indemnify any such person serving in
any such capacity who was or is a party or is threatened to be made a party to
any threatened, pending or completed action or suit by or in the right of the
corporation to procure a judgment in its favor, against expenses actually and
reasonably incurred in connection with the defense or settlement of such action
or suit if he acted in good faith and in a manner he reasonably believed to be
in or not opposed to the best interest of the corporation and except that no
indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or such other
court in which such action or suit was brought shall determine upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnify for such
expenses which the Court of Chancery or such other court shall deem proper.

          Section 102(b)(7) of the DGCL permits a corporation to include in its
certificate of incorporation a provision eliminating or limiting the personal
liability of a director to the corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director, provided that such provision
shall not eliminate or limit the liability of a director (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL (relating to
unlawful payment of dividends and unlawful stock purchase and redemption) or
(iv) for any transaction from which the director derived an improper personal
benefit.

          The Registrant's Certificate of Incorporation provides that the
liability of the directors shall be eliminated to the fullest extent permissible
by Section 102(b)(7) of the DGCL, as amended. The Certificate of Incorporation
further provides that the Registrant shall indemnify its directors and officers
to the fullest extent permitted by Section 145 of the DGCL, as amended.

          Reference is made to the form of Indemnification Agreement
incorporated by reference as Exhibit 10 to this Registration Statement for
information regarding indemnification of directors and officers under certain
circumstances.

Item 7.   Exemption from Registration Claimed.
          ----------------------------------- 

          Not applicable.

Item 8.   Exhibits.
          -------- 

          The following exhibits are filed as a part of this Registration
Statement:

Exhibit
Number              Description
------              -----------

4.1                 --Specimen of Common Stock Certificate.(1)
4.2                 --Restated Equity Incentive Plan, as amended.(2)
4.3                 --1996 Non-Employee Directors Automatic Stock Option
                      Plan.(2)
4.4                 --1997 Equity Incentive Plan for Non-Employee Directors.(3)
5                   --Opinion of Ropes & Gray.
10                  --Form of Director Indemnification Agreement(1)
23.1                --Consent of Independent Accountants.
23.2                --Consent of Ropes & Gray (Included in Exhibit 5).
24                  --Powers of Attorney (contained on the Signature Page of
                      this Registration Statement).

                                      II-2
<PAGE>
 
(1)       Previously filed with the Company's Registration Statement on Form 
          S-1, effective November 5, 1996 (S.E.C. Reg. No. 333-04388) and
          incorporated by reference herein.

(2)       Previously filed with the Company's Annual Report on Form 10-K for the
          fiscal year ended December 31, 1997 and incorporated by reference
          herein.

(3)       Previously filed with the Company's Registration Statement on Form S-
          8, filed on February 14, 1997 (S.E.C. Reg. No. 333-21875) and
          incorporated by reference herein.

Item 9.   Undertakings.
          ------------ 

          (a)  The undersigned Registrant hereby undertakes:

               (1)  to file, during any period in which offers or sales are
          being made, a post-effective amendment to this Registration Statement;
          (i) to include any prospectus required by Section 10(a)(3) of the
          Securities Act of 1933; (ii) to reflect in the prospectus any facts or
          events arising after the effective date of the Registration Statement
          (or the most recent post-effective amendment thereof), which,
          individually or in the aggregate, represent a fundamental change in
          the information set forth in the Registration Statement; and (iii) to
          include any material information with respect to the plan of
          distribution not previously disclosed in the Registration Statement or
          any material change to such information in the Registration Statement;
          provided, however, that paragraphs (a)(1)(i) and (ii) shall not apply
          if the information required to be included in a post-effective
          amendment by those paragraphs is contained in periodic reports filed
          by the Registrant pursuant to section 13 or section 15(d) of the
          Exchange Act that are incorporated by reference in the Registration
          Statement.

               (2)  that, for the purpose of determining any liability under the
          Securities Act of 1933, each such post-effective amendment shall be
          deemed to be a new Registration Statement relating to the securities
          offered herein, and the offering of such securities at that time shall
          be deemed to be the initial bona fide offering thereof;

               (3)  to remove from registration by means of a post-effective
          amendment any of the securities being registered which remain unsold
          at the termination of the offering.

          (b)  The undersigned Registrant hereby undertakes that, for purposes
          of determining any liability under the Securities Act of 1933, each
          filing of the Registrant's annual report pursuant to Section 13(a) or
          Section 15(d) of the Exchange Act that is incorporated by reference in
          the Registration Statement shall be deemed to be a new Registration
          Statement relating to the securities offered therein, and the offering
          of such securities at that time shall be deemed to be the initial bona
          fide offering thereof.

          (c)  Insofar as indemnification for liabilities arising under the
          Securities Act of 1933 may be permitted to directors, officers and
          controlling persons of the Registrant pursuant to the foregoing
          provisions, or otherwise, the Registrant has been advised that in the
          opinion of the Securities and Exchange Commission such indemnification
          is against public policy as expressed in the Act and is, therefore,
          unenforceable. In the event that a claim for indemnification against
          such liabilities (other than the payment by the Registrant of expenses
          incurred or paid by a director, officer or controlling person of the
          Registrant in the successful defense of any action, suit or
          proceeding) is asserted by such director, officer or controlling
          person in connection with the securities being registered, the
          Registrant will, unless in the opinion of its counsel the matter has
          been settled by controlling precedent, submit to a court of
          appropriate jurisdiction the question whether such indemnification by
          it is against public policy as expressed in the Act and will be
          governed by the final adjudication of such issue.

                                      II-3
<PAGE>
 
                                  SIGNATURES

     Pursuant to the requirements of the Securities Act, the Company has duly
caused this Registration Statement on Form S-8 to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Bellevue, State of
Washington on the 15th day of April, 1998.

                                   Advanced Radio Telecom Corp.


                                   By: /s/ Henry C. Hirsch
                                       -------------------------
                                   Title:  Chairman, Chief Executive Officer
                                           and Director

                              POWERS OF ATTORNEY

     Each person whose signature appears below hereby authorizes and appoints
Henry C. Hirsch, Thomas A. Grina and Thomas M. Walker, and each of them, with
full power of substitution and full power to act without the other, as his true
and lawful attorney-in-fact and agent to act in his name, place and stead and to
execute in the name and on behalf of each person, individually and in each
capacity stated below, and to file, any and all amendments to this Registration
Statement, including any and all post-effective amendments and any subsequent
Registration Statement for the same offering which may be filed under Rule
462(b).

  Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities indicated
below on the 15th day of April, 1998.

<TABLE>
<CAPTION>
SIGNATURE                         TITLE                                DATE
---------                         -----                                --------------
<S>                               <C>                                  <C>
/s/ Henry C. Hirsch               Chairman, Chief Executive Officer    April 15, 1998
----------------------------
Henry C. Hirsch                   and Director
 
/s/ Thomas A. Grina               Executive Vice President and         April 15, 1998
----------------------------
Thomas A. Grina                   Chief Financial Officer
 
/s/ Vernon L. Fotheringham        Vice-Chairman and Director           April 15, 1998
----------------------------
Vernon L. Fotheringham
 
/s/ James C. Cook                 Director                             April 15, 1998
----------------------------
James C. Cook
 
/s/ Mark C. Demetree              Director                             April 15, 1998
----------------------------
Mark C. Demetree
 
/s/ Andrew I. Fillat              Director                             April 15, 1998
----------------------------
Andrew I. Fillat
 
/s/ James B. Murray               Director                             April 15, 1998
----------------------------
James B. Murray
 
/s/ Alan Z. Senter                Director                             April 15, 1998
----------------------------
Alan Z. Senter
</TABLE>

                                      II-4
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 20190}]
{"company-data": {"conformed-name": "ADVANCED RADIO TELECOM CORP", "cik": "0001010286", "assigned-sic": "4841", "irs-number": "521869023", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-50155", "film-number": "98594480"}, "business-address": {"street1": "500 108TH AVE NE", "street2": "SUITE 2600", "city": "BELLEVUE", "state": "WA", "zip": "98004", "phone": "2066888700"}, "mail-address": {"street1": "500 108TH AVENUE NE", "street2": "SUITE 2600", "city": "BELLEVUE", "state": "WA", "zip": "98004"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON APRIL 15, 1998.
                                                           REGISTRATION NO. 333-
================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, DC 20549

                                   FORM S-8
                                        
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                         ADVANCED RADIO TELECOM CORP.
            (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
DELAWARE                             4812                      52-1869023
(STATE OR OTHER JURISDICTION      (PRIMARY STANDARD INDUSTRIAL      (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION)      CLASSIFICATION CODE NUMBER)     IDENTIFICATION NO.)
500 108TH AVENUE NE, SUITE 2600, BELLEVUE, WASHINGTON 98004  (425) 688-8700
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                            THOMAS M. WALKER, ESQ.
                                GENERAL COUNSEL
                        500 108TH AVENUE NE, SUITE 2600
                          BELLEVUE, WASHINGTON  98004
                     (425) 688-8700 / (425) 990-1642 (FAX)
(NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)

                       COPIES OF ALL COMMUNICATIONS TO:

                              MARY E. WEBER, ESQ.
                                 ROPES & GRAY
                            ONE INTERNATIONAL PLACE
                            BOSTON, MA  02110-2624
                     (617) 951-7000 / (617) 951-7050 (FAX)
                        CALCULATION OF REGISTRATION FEE
==================================================================================================================================
   Title of Securities      Amount to be         Proposed maximum               Proposed maximum               Amount of
     to be registered        registered      offering price per share/(1)/  aggregate offering price/(1)/  registration fee/(2)/
----------------------------------------------------------------------------------------------------------------------------------
Common Stock, par         3,100,000              $14.6563                        $45,434,530                 $13,403.19
 value, $.001 (including
 Junior Preferred Stock
   Purchase Rights)
==================================================================================================================================
(1)  Estimated solely for the purpose of determining the registration fee
     pursuant to Rule 457(c) for the purpose of calculating the registration fee
     based on the average of the high and low prices of the Registrant's Common
     Stock reported on the Nasdaq National Market on April 13, 1998.
(2)  An additional filing fee of $4,598.01 was previously paid for 1,475,000
     shares registered for issuance under the Restated Equity Incentive Plan and
     the 1996 Non-Employee Directors Automatic Stock Option Plan under
     Registration Statement 333-21875. Of the $4,598.01, $4,364.08 represents
     the filing fee for the 1,400,000 shares registered for issuance under the
     Restated Equity Incentive Plan and $233.93 represents the filing fee for
     the 75,000 shares registered for issuance under the 1996 Non-Employee
     Directors Automatic Stock Option Plan.

     Pursuant to Rule 429 under the Securities Act of 1933, the Prospectus
included herein also relates to a total of 1,400,000 shares of the Registrant
that are registered under Registration Statement on Form S-8 No. 333-21875,
which was filed on February 14, 1997.  This Registration Statement constitutes
Post-Effective Amendment No. 1 to Registration Statement on Form S-8 No. 333-
21875 pursuant to which any outstanding shares previously registered under
Registration Statement on Form S-8 No. 333-21875 may be offered and sold,
together with the securities registered hereunder, through the use of the
combined Prospectus included herein.  In the event any of such previously
registered shares are offered and sold prior to the effective date of this
Registration Statement, the amount of such shares will not be included in any
Prospectus hereunder.
================================================================================
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference.
          --------------------------------------- 

          The Registrant hereby incorporates the following documents herein by
reference:

          1)   The Company's Annual Report on Form 10-K for the fiscal year
               ended December 31, 1997.
     
          2)   The Company's Current Report on Form 8-K filed with the
               Commission on March 5, 1998.

          3)   The description of the Company's Common Stock and Junior
               Preferred Stock Purchase Rights contained in the Company's
               Registration Statements on Forms 8-A and 8-A/A (File No. 000-
               21091) filed under Section 12 of the Securities Exchange Act of
               1934, as amended (the "Exchange Act").

          All other documents subsequently filed by the Company pursuant to
Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold, shall be deemed
to be incorporated by reference in this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained herein
or in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein or in any subsequently
filed document that also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

          The Registrant will provide without charge to each participant those
documents containing information regarding the respective Plans required by Item
1 of the Form S-8 as specified by Rule 428(b). The Registrant will also provide
without charge, upon the oral or written request of any particpant, a copy of
any and all documents that have been incorporated by reference in Item 3 of Part
II of this Registration Statement. Such documents may be obtained by writing to
Advanced Radio Telecom Corp., 500 108th Avenue, N.E., Suite 2600, Bellevue,
Washington 98004 or by calling (425) 688-8700. In accordance with Rule 428 and
the requirements of Part I of Form S-8, the Plans and any documents incorporated
by reference are not being filed with the Securities and Exchange Commission
("Commission") either as part of this Registration Statement or as prospectuses
or prospectus supplements pursuant to Rule 424. Upon request, the Registrant
shall furnish to the Commission or its staff a copy of copies of all of the
above-referenced documents.

Item 4 .  Description of Securities.
          ------------------------- 

          Not required.

Item 5.   Interests of Named Experts and Counsel.
          -------------------------------------- 

          Not required.

Item 6.   Indemnification of Directors and Officers.
          ----------------------------------------- 

          Section 145 of the Delaware General Corporation Law, as amended (the
"DGCL"), provides that a corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal or investigative
(other than an action by or in the right of the corporation) by reason of the
fact that he is or was a director, officer, employee or agent of the
corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, against
expenses (including attorneys' fees), judgments, fines and amount paid in
settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
corporation, and, with respect to any criminal action or proceeding, had not
reasonable cause to believe his conduct was unlawful. Section 145 further
provides that a corporation similarly may indemnify any such person serving in
any such capacity who was or is a party or is threatened to be made a party to
any threatened, pending or completed action or suit by or in the right of the
corporation to procure a judgment in its favor, against expenses actually and
reasonably incurred in connection with the defense or settlement of such action
or suit if he acted in good faith and in a manner he reasonably believed to be
in or not opposed to the best interest of the corporation and except that no
indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or such other
court in which such action or suit was brought shall determine upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnify for such
expenses which the Court of Chancery or such other court shall deem proper.

          Section 102(b)(7) of the DGCL permits a corporation to include in its
certificate of incorporation a provision eliminating or limiting the personal
liability of a director to the corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director, provided that such provision
shall not eliminate or limit the liability of a director (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL (relating to
unlawful payment of dividends and unlawful stock purchase and redemption) or
(iv) for any transaction from which the director derived an improper personal
benefit.

          The Registrant's Certificate of Incorporation provides that the
liability of the directors shall be eliminated to the fullest extent permissible
by Section 102(b)(7) of the DGCL, as amended. The Certificate of Incorporation
further provides that the Registrant shall indemnify its directors and officers
to the fullest extent permitted by Section 145 of the DGCL, as amended.

          Reference is made to the form of Indemnification Agreement
incorporated by reference as Exhibit 10 to this Registration Statement for
information regarding indemnification of directors and officers under certain
circumstances.

Item 7.   Exemption from Registration Claimed.
          ----------------------------------- 

          Not applicable.

Item 8.   Exhibits.
          -------- 

          The following exhibits are filed as a part of this Registration
Statement:

Exhibit
Number              Description
------              -----------

4.1                 --Specimen of Common Stock Certificate.(1)
4.2                 --Restated Equity Incentive Plan, as amended.(2)
4.3                 --1996 Non-Employee Directors Automatic Stock Option
                      Plan.(2)
4.4                 --1997 Equity Incentive Plan for Non-Employee Directors.(3)
5                   --Opinion of Ropes & Gray.
10                  --Form of Director Indemnification Agreement(1)
23.1                --Consent of Independent Accountants.
23.2                --Consent of Ropes & Gray (Included in Exhibit 5).
24                  --Powers of Attorney (contained on the Signature Page of
                      this Registration Statement).

                                      II-2
(1)       Previously filed with the Company's Registration Statement on Form 
          S-1, effective November 5, 1996 (S.E.C. Reg. No. 333-04388) and
          incorporated by reference herein.

(2)       Previously filed with the Company's Annual Report on Form 10-K for the
          fiscal year ended December 31, 1997 and incorporated by reference
          herein.

(3)       Previously filed with the Company's Registration Statement on Form S-
          8, filed on February 14, 1997 (S.E.C. Reg. No. 333-21875) and
          incorporated by reference herein.

Item 9.   Undertakings.
          ------------ 

          (a)  The undersigned Registrant hereby undertakes:

               (1)  to file, during any period in which offers or sales are
          being made, a post-effective amendment to this Registration Statement;
          (i) to include any prospectus required by Section 10(a)(3) of the
          Securities Act of 1933; (ii) to reflect in the prospectus any facts or
          events arising after the effective date of the Registration Statement
          (or the most recent post-effective amendment thereof), which,
          individually or in the aggregate, represent a fundamental change in
          the information set forth in the Registration Statement; and (iii) to
          include any material information with respect to the plan of
          distribution not previously disclosed in the Registration Statement or
          any material change to such information in the Registration Statement;
          provided, however, that paragraphs (a)(1)(i) and (ii) shall not apply
          if the information required to be included in a post-effective
          amendment by those paragraphs is contained in periodic reports filed
          by the Registrant pursuant to section 13 or section 15(d) of the
          Exchange Act that are incorporated by reference in the Registration
          Statement.

               (2)  that, for the purpose of determining any liability under the
          Securities Act of 1933, each such post-effective amendment shall be
          deemed to be a new Registration Statement relating to the securities
          offered herein, and the offering of such securities at that time shall
          be deemed to be the initial bona fide offering thereof;

               (3)  to remove from registration by means of a post-effective
          amendment any of the securities being registered which remain unsold
          at the termination of the offering.

          (b)  The undersigned Registrant hereby undertakes that, for purposes
          of determining any liability under the Securities Act of 1933, each
          filing of the Registrant's annual report pursuant to Section 13(a) or
          Section 15(d) of the Exchange Act that is incorporated by reference in
          the Registration Statement shall be deemed to be a new Registration
          Statement relating to the securities offered therein, and the offering
          of such securities at that time shall be deemed to be the initial bona
          fide offering thereof.

          (c)  Insofar as indemnification for liabilities arising under the
          Securities Act of 1933 may be permitted to directors, officers and
          controlling persons of the Registrant pursuant to the foregoing
          provisions, or otherwise, the Registrant has been advised that in the
          opinion of the Securities and Exchange Commission such indemnification
          is against public policy as expressed in the Act and is, therefore,
          unenforceable. In the event that a claim for indemnification against
          such liabilities (other than the payment by the Registrant of expenses
          incurred or paid by a director, officer or controlling person of the
          Registrant in the successful defense of any action, suit or
          proceeding) is asserted by such director, officer or controlling
          person in connection with the securities being registered, the
          Registrant will, unless in the opinion of its counsel the matter has
          been settled by controlling precedent, submit to a court of
          appropriate jurisdiction the question whether such indemnification by
          it is against public policy as expressed in the Act and will be
          governed by the final adjudication of such issue.

                                      II-3
SIGNATURES

     Pursuant to the requirements of the Securities Act, the Company has duly
caused this Registration Statement on Form S-8 to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Bellevue, State of
Washington on the 15th day of April, 1998.

                                   Advanced Radio Telecom Corp.

                                   By: /s/ Henry C. Hirsch
                                       -------------------------
                                   Title:  Chairman, Chief Executive Officer
                                           and Director

                              POWERS OF ATTORNEY

     Each person whose signature appears below hereby authorizes and appoints
Henry C. Hirsch, Thomas A. Grina and Thomas M. Walker, and each of them, with
full power of substitution and full power to act without the other, as his true
and lawful attorney-in-fact and agent to act in his name, place and stead and to
execute in the name and on behalf of each person, individually and in each
capacity stated below, and to file, any and all amendments to this Registration
Statement, including any and all post-effective amendments and any subsequent
Registration Statement for the same offering which may be filed under Rule
462(b).

  Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities indicated
below on the 15th day of April, 1998.
SIGNATURE                         TITLE                                DATE
---------                         -----                                --------------
/s/ Henry C. Hirsch               Chairman, Chief Executive Officer    April 15, 1998
----------------------------
Henry C. Hirsch                   and Director
 
/s/ Thomas A. Grina               Executive Vice President and         April 15, 1998
----------------------------
Thomas A. Grina                   Chief Financial Officer
 
/s/ Vernon L. Fotheringham        Vice-Chairman and Director           April 15, 1998
----------------------------
Vernon L. Fotheringham
 
/s/ James C. Cook                 Director                             April 15, 1998
----------------------------
James C. Cook
 
/s/ Mark C. Demetree              Director                             April 15, 1998
----------------------------
Mark C. Demetree
 
/s/ Andrew I. Fillat              Director                             April 15, 1998
----------------------------
Andrew I. Fillat
 
/s/ James B. Murray               Director                             April 15, 1998
----------------------------
James B. Murray
 
/s/ Alan Z. Senter                Director                             April 15, 1998
----------------------------
Alan Z. Senter
II-4