As filed with the Securities and Exchange Commission on October 8, 1998
                                                    Registration No. 333-_______
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           ---------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                           ---------------------------

                                  CD RADIO INC.
             (Exact name of registrant as specified in its charter)

           DELAWARE                                              52-170027
(State or other jurisdiction of                                (IRS Employer
incorporation or organization)                               Identification No.)

                     1180 AVENUE OF THE AMERICAS, 14TH FLOOR
                               NEW YORK, NY 10036
                                 (212) 899-5000
    (Address, including zip code, and telephone number, including area code,
                  of Registrant's principal executive offices)

                        CD RADIO INC. 401(K) SAVINGS PLAN
                            (Full title of the Plan)

                               PATRICK L. DONNELLY
             EXECUTIVE VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                                  CD RADIO INC.
                           1180 AVENUE OF THE AMERICAS
                                   14TH FLOOR
                            NEW YORK, NEW YORK 10036
                                 (212) 899-5000
 (Name, address, including zip code, and telephone number, including area code,
                              of agent for service)
                           ---------------------------
                                   Copies to:

                               MITCHELL S. FISHMAN
                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 AVENUE OF THE AMERICAS
                          NEW YORK, NEW YORK 10019-6064
                                 (212) 373-3000
                           ---------------------------
<TABLE>
<CAPTION>
                                                     CALCULATION OF REGISTRATION FEE

       TITLE OF EACH CLASS          AMOUNT TO BE         PROPOSED MAXIMUM              PROPOSED MAXIMUM             AMOUNT OF
OF SECURITIES TO BE REGISTERED (1)   REGISTERED    OFFERING PRICE PER SHARE (2)    AGGREGATE OFFERING PRICE    REGISTRATION FEE (2)
====================================================================================================================================
<S>                                    <C>                   <C>                          <C>                        <C> 
 Common Stock, par value $.001... 

 Preferred Stock Purchase Rights
 (3).............................      50,000                $16-7/8                      $843,750                   $249
====================================================================================================================================
</TABLE>

(1)      In addition, pursuant to Rule 416 under the Securities Act of 1933,
         this registration statement also covers an undeterminate amount of
         interests to be offered or sold pursuant to the employee benefit plan
         described herein.
(2)      The proposed maximum offering price per share and the registration fee
         were calculated in accordance with Rule 457(c) and (h) based on the
         closing price for shares of the registrant's common stock, par value
         $.001 per share (the "Common Stock"), on October 7, 1998, as reported
         by The Nasdaq Stock Market, Inc. which was $16-7/8.
(3)      Each Preferred Stock Purchase Right (the "Rights") represents the right
         to purchase one one-hundredth of a share of Series B Preferred Stock
         for each share of Common Stock. The Rights are appurtenant to and trade
         with the Common Stock. The value attributable to the Rights, if any, is
         reflected in the value of the Common Stock and the registration fee for
         the Rights is included in the fee for the Common Stock.

================================================================================
<PAGE>

                                                                               2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

         The following documents filed by the Company with the Securities and
Exchange Commission (the "Commission") are incorporated herein by reference:

         1. The Company's Annual Report on Form 10-K for the year ended December
            31, 1997.

         2. The Company's Quarterly Report on Form 10-Q for the quarter ended
            March 31, 1998.

         3. The Company's Quarterly Report on Form 10-Q for the quarter ended
            June 30, 1998.

         4. The Company's Current Report on Form 8-K dated June 1, 1998.

         5. The Report of PricewaterhouseCoopers L.L.P., Independent 
            Accountants, included as Exhibit 15.1 to Amendment No. 3 to the
            Company's Registration Statement on Form S-3 dated October 7, 1998
            (Registration No. 333-52893).

         All other documents filed by the Company with the Commission pursuant
to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934,
as amended, subsequent to the date of this registration statement and prior to
the filing of a post-effective amendment which indicates that all securities
registered hereby 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 part hereof from the date of filing of such
documents. Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded to
the extent that a statement contained in this registration statement or in any
other subsequently filed document which also is incorporated or 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 Company hereby undertakes to provide without charge to each
participant in the CD Radio 401(k) Savings Plan (the "Plan"), on the written or
oral request of any such person, a copy of any or all of the documents referred
to above which have been or may be incorporated in this registration statement
by reference, other than exhibits to such documents (unless such exhibits are
specifically incorporated by reference in such documents). Requests for such
copies should be directed to Secretary, CD Radio Inc., 1180 Avenue of the
Americas, New York, New York 10036, telephone number: (212) 899-5000.

ITEM 4.  DESCRIPTION OF SECURITIES

         Not Applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Patrick L. Donnelly, Esq., whose legal opinion with respect to the
securities registered hereunder is filed as Exhibit 5.1 hereto, is an employee
of the Company and may participate in the Plan and other benefit plans
established by the Company.
<PAGE>

                                                                               3

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation Law authorizes a
corporation to indemnify its directors, officers, employees and agents against
certain liabilities they may incur in such capacities, including liabilities
under the Securities Act of 1933, as amended, provided they act in good faith
and in a manner reasonably believed to be in or not opposed to the best
interests of the corporation. The Company's Amended and Restated Certificate of
Incorporation and Amended and Restated Bylaws require the Company to indemnify
its officers and directors to the full extent permitted by Delaware law,
provided that such officers or directors acted in good faith and in a manner
reasonably believed to be in, or not opposed to, the best interests of the
Company and, with respect to any criminal action or proceeding, with no
reasonable cause to expect his or her action was unlawful. Also, indemnification
under the Company's Amended and Restated Certificate of Incorporation and
Amended and Restated Bylaws will not be available where an officer or director
is adjudged to be liable for negligence or misconduct in the performance of his
or her duty to the Company. The Company's Amended and Restated Certificate of
Incorporation and Amended and Restated Bylaws also provide for the Company to
purchase and maintain insurance on behalf of any past or current officer or
director against any liability that may be asserted or arise from his or her
role as an officer or director.

         Section 102 of the Delaware General Corporation Law authorizes a
corporation to limit or eliminate its directors' liability to the corporation or
its stockholders for monetary damages for breaches of fiduciary duties, other
than for (i) breaches of the duty of loyalty, (ii) acts or omissions involving
bad faith, intentional misconduct or knowing violations of the law, (iii)
unlawful payments of dividends, stock purchases or redemptions, or (iv)
transactions from which a director derives an improper personal benefit. The
Company's Amended and Restated Certificate of Incorporation contains provisions
limiting the liability of the directors to the Company and to its stockholders
to the full extent permitted by Delaware law.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not Applicable.

ITEM 8.  EXHIBITS

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

4.1          Form of Certificate for shares of Common Stock (incorporated by
             reference to Exhibit 4.3 to the Company's Registration Statement on
             Form S-1 (File No. 33- 74782) (the "S-1 Registration Statement")).

4.2          Rights Agreement, dated as of October 22, 1997, between the Company
             and Continental Stock Transfer & Trust Company, as Rights Agent
             (incorporated by reference to Exhibit 1 to the Company's
             Registration Statement on Form 8-A filed with the Commission on
             October 30, 1997 (the "Form 8-A")).

4.3          Form of Right Certificate (incorporated by reference to Exhibit B
             to Exhibit 1 to the Form 8-A).

4.4          CD Radio Inc. 401(k) Savings Plan.

5.1          Opinion of Patrick L. Donnelly, Executive Vice President, General
             Counsel and Secretary of the Company, regarding the legality of the
             Common Stock being registered.

23.1         Consent of Patrick L. Donnelly, Executive Vice President,
             General Counsel and Secretary of the Company (included in
             Exhibit 5.1).

23.2         Consent of PriceWaterhouseCoopers LLP.
<PAGE>

                                                                               4

24.1         Power of Attorney (included on signature page).


ITEM 9.  UNDERTAKINGS

         (a) The undersigned registrant hereby undertakes: (i) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this registration statement to include any material information with respect
to the plan of distribution not previously disclosed in this registration
statement or any material change to such information in this registration
statement; (ii) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended, each such post-effective amendment 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; and (iii) 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, as amended, each
filing of the registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Securities Exchange Act of 1934, as amended, that is incorporated
by reference in this 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, as amended, may be permitted to directors, officers and
controlling persons of the registrant pursuant to the foregoing provisions, the
registrant's Amended and Restated Certificate of Incorporation or Amended and
Restated Bylaws, 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.
<PAGE>

                                                                               5

                                   SIGNATURES


         Pursuant to the requirements of the Securities Act of 1933, as amended,
the registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York, on October 8, 1998.

                                                 CD RADIO INC.


                                                 By: /s/ Andrew J. Greenebaum
                                                 ----------------------------
                                                 Andrew J. Greenebaum
                                                 Executive Vice President and
                                                 Chief Financial Officer

         KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below hereby constitutes and appoints Andrew J. Greenebaum and Patrick
L. Donnelly, and each of them, his or her true and lawful agent, proxy and
attorney-in-fact, each acting alone with full power of substitution and
resubstitution, for him or her and in his or her name, place and sterad, in any
and all capacities, to (i) act on, sign and file with the Commission any and all
amendments (including post-effective amendments) to this registration statement
together with all schedules and exhibits thereto, (ii) act on, sign and file
such certificates, instruments, agreements and other documents as may be
necessary or appropriate in connection therewith, and (iii) take any and all
actions which may be necessary or appropriate in connection therewith, granting
unto such agents, proxies and attorneys-in-fact, and each of them, full power
and authority to do and perform each and every act and thing necessary or
appropriate to be done, as fully for all intents and purposes as he or she might
or could do in person, hereby approving, ratifying and confirming all that such
agents, proxies and attorneys-in-fact, any of them or any of his or her or their
substitutes may lawfully do or cause to be done by virtue thereof.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this registration statement has been signed by the following persons in the
capacities and on the dates indicated:


     Signatures                         Title                          Date
     ----------                         -----                          ----

/s/ David Margolese          Chairman and Chief Executive        October 8, 1998
------------------------     Officer (Principal Executive
David Margolese              Officer)
                             

/s/ Robert D. Briskman       Director                            October 8, 1998
------------------------
Robert D. Briskman
<PAGE>

                                                                               6

     Signatures                         Title                          Date
     ----------                         -----                          ----

/s/ Lawrence F. Gilberti     Director                            October 8, 1998
------------------------
Lawrence F. Gilberti                 


/s/ Joseph V. Vittoria       Director                            October 8, 1998
------------------------
Joseph V. Vittoria


/s/ Ralph W. Whitworth       Director                            October 8, 1998
------------------------
Ralph W. Whitworth


/s/Andrew J. Greenebaum      Executive Vice President and        October 8, 1998
------------------------     Chief Financial Officer
Andrew J. Greenebaum         (Principal Financial Officer)
                             

/s/ John T. McClain          Vice President and Controller       October 8, 1998
------------------------     (Principal Accounting Officer)
John T. McClain              
<PAGE>

                                                                               7

                                INDEX TO EXHIBITS

Exhibits
--------

4.1          Form of Certificate for shares of Common Stock (incorporated by
             reference to Exhibit 4.3 to the Company's Registration Statement on
             Form S-1 (File No. 33- 74782) (the "S-1 Registration Statement")).

4.2          Rights Agreement, dated as of October 22, 1997, between the Company
             and Continental Stock Transfer & Trust Company, as Rights Agent
             (incorporated by reference to Exhibit 1 to the Company's
             Registration Statement on Form 8-A filed with the Commission on
             October 30, 1997 (the "Form 8-A")).

4.3          Form of Right Certificate (incorporated by reference to Exhibit B
             to Exhibit 1 to the Form 8-A).

4.4          CD Radio Inc. 401(k) Savings Plan.

5.1          Opinion of Patrick L. Donnelly, Executive Vice President, General
             Counsel and Secretary of the Company, regarding the legality of the
             Common Stock being registered (filed herewith).

23.1         Consent of Patrick L. Donnelly, Executive Vice President,
             General Counsel and Secretary of the Company (included in
             Exhibit 5.1).

23.2         Consent of PriceWaterhouseCoopers LLP.

24.1         Power of Attorney (included on signature page).
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 19664}]
{"company-data": {"conformed-name": "CD RADIO INC", "cik": "0000908937", "assigned-sic": "4832", "irs-number": "521700207", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-65473", "film-number": "98722793"}, "business-address": {"street1": "1180 AVENUE OF THE AMERICAS", "street2": "14TH FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10036", "phone": "2128995000"}, "mail-address": {"street1": "1001 22ND STREET NW 6TH FLOOR", "city": "WAHINGTON", "state": "DC", "zip": "20037"}}
As filed with the Securities and Exchange Commission on October 8, 1998
                                                    Registration No. 333-_______
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           ---------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                           ---------------------------

                                  CD RADIO INC.
             (Exact name of registrant as specified in its charter)

           DELAWARE                                              52-170027
(State or other jurisdiction of                                (IRS Employer
incorporation or organization)                               Identification No.)

                     1180 AVENUE OF THE AMERICAS, 14TH FLOOR
                               NEW YORK, NY 10036
                                 (212) 899-5000
    (Address, including zip code, and telephone number, including area code,
                  of Registrant's principal executive offices)

                        CD RADIO INC. 401(K) SAVINGS PLAN
                            (Full title of the Plan)

                               PATRICK L. DONNELLY
             EXECUTIVE VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                                  CD RADIO INC.
                           1180 AVENUE OF THE AMERICAS
                                   14TH FLOOR
                            NEW YORK, NEW YORK 10036
                                 (212) 899-5000
 (Name, address, including zip code, and telephone number, including area code,
                              of agent for service)
                           ---------------------------
                                   Copies to:

                               MITCHELL S. FISHMAN
                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 AVENUE OF THE AMERICAS
                          NEW YORK, NEW YORK 10019-6064
                                 (212) 373-3000
                           ---------------------------
CALCULATION OF REGISTRATION FEE

       TITLE OF EACH CLASS          AMOUNT TO BE         PROPOSED MAXIMUM              PROPOSED MAXIMUM             AMOUNT OF
OF SECURITIES TO BE REGISTERED (1)   REGISTERED    OFFERING PRICE PER SHARE (2)    AGGREGATE OFFERING PRICE    REGISTRATION FEE (2)
====================================================================================================================================
Common Stock, par value $.001... 

 Preferred Stock Purchase Rights
 (3).............................      50,000                $16-7/8                      $843,750                   $249
====================================================================================================================================
(1)      In addition, pursuant to Rule 416 under the Securities Act of 1933,
         this registration statement also covers an undeterminate amount of
         interests to be offered or sold pursuant to the employee benefit plan
         described herein.
(2)      The proposed maximum offering price per share and the registration fee
         were calculated in accordance with Rule 457(c) and (h) based on the
         closing price for shares of the registrant's common stock, par value
         $.001 per share (the "Common Stock"), on October 7, 1998, as reported
         by The Nasdaq Stock Market, Inc. which was $16-7/8.
(3)      Each Preferred Stock Purchase Right (the "Rights") represents the right
         to purchase one one-hundredth of a share of Series B Preferred Stock
         for each share of Common Stock. The Rights are appurtenant to and trade
         with the Common Stock. The value attributable to the Rights, if any, is
         reflected in the value of the Common Stock and the registration fee for
         the Rights is included in the fee for the Common Stock.

================================================================================
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

         The following documents filed by the Company with the Securities and
Exchange Commission (the "Commission") are incorporated herein by reference:

         1. The Company's Annual Report on Form 10-K for the year ended December
            31, 1997.

         2. The Company's Quarterly Report on Form 10-Q for the quarter ended
            March 31, 1998.

         3. The Company's Quarterly Report on Form 10-Q for the quarter ended
            June 30, 1998.

         4. The Company's Current Report on Form 8-K dated June 1, 1998.

         5. The Report of PricewaterhouseCoopers L.L.P., Independent 
            Accountants, included as Exhibit 15.1 to Amendment No. 3 to the
            Company's Registration Statement on Form S-3 dated October 7, 1998
            (Registration No. 333-52893).

         All other documents filed by the Company with the Commission pursuant
to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934,
as amended, subsequent to the date of this registration statement and prior to
the filing of a post-effective amendment which indicates that all securities
registered hereby 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 part hereof from the date of filing of such
documents. Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded to
the extent that a statement contained in this registration statement or in any
other subsequently filed document which also is incorporated or 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 Company hereby undertakes to provide without charge to each
participant in the CD Radio 401(k) Savings Plan (the "Plan"), on the written or
oral request of any such person, a copy of any or all of the documents referred
to above which have been or may be incorporated in this registration statement
by reference, other than exhibits to such documents (unless such exhibits are
specifically incorporated by reference in such documents). Requests for such
copies should be directed to Secretary, CD Radio Inc., 1180 Avenue of the
Americas, New York, New York 10036, telephone number: (212) 899-5000.

ITEM 4.  DESCRIPTION OF SECURITIES

         Not Applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Patrick L. Donnelly, Esq., whose legal opinion with respect to the
securities registered hereunder is filed as Exhibit 5.1 hereto, is an employee
of the Company and may participate in the Plan and other benefit plans
established by the Company.
3

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation Law authorizes a
corporation to indemnify its directors, officers, employees and agents against
certain liabilities they may incur in such capacities, including liabilities
under the Securities Act of 1933, as amended, provided they act in good faith
and in a manner reasonably believed to be in or not opposed to the best
interests of the corporation. The Company's Amended and Restated Certificate of
Incorporation and Amended and Restated Bylaws require the Company to indemnify
its officers and directors to the full extent permitted by Delaware law,
provided that such officers or directors acted in good faith and in a manner
reasonably believed to be in, or not opposed to, the best interests of the
Company and, with respect to any criminal action or proceeding, with no
reasonable cause to expect his or her action was unlawful. Also, indemnification
under the Company's Amended and Restated Certificate of Incorporation and
Amended and Restated Bylaws will not be available where an officer or director
is adjudged to be liable for negligence or misconduct in the performance of his
or her duty to the Company. The Company's Amended and Restated Certificate of
Incorporation and Amended and Restated Bylaws also provide for the Company to
purchase and maintain insurance on behalf of any past or current officer or
director against any liability that may be asserted or arise from his or her
role as an officer or director.

         Section 102 of the Delaware General Corporation Law authorizes a
corporation to limit or eliminate its directors' liability to the corporation or
its stockholders for monetary damages for breaches of fiduciary duties, other
than for (i) breaches of the duty of loyalty, (ii) acts or omissions involving
bad faith, intentional misconduct or knowing violations of the law, (iii)
unlawful payments of dividends, stock purchases or redemptions, or (iv)
transactions from which a director derives an improper personal benefit. The
Company's Amended and Restated Certificate of Incorporation contains provisions
limiting the liability of the directors to the Company and to its stockholders
to the full extent permitted by Delaware law.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not Applicable.

ITEM 8.  EXHIBITS

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

4.1          Form of Certificate for shares of Common Stock (incorporated by
             reference to Exhibit 4.3 to the Company's Registration Statement on
             Form S-1 (File No. 33- 74782) (the "S-1 Registration Statement")).

4.2          Rights Agreement, dated as of October 22, 1997, between the Company
             and Continental Stock Transfer & Trust Company, as Rights Agent
             (incorporated by reference to Exhibit 1 to the Company's
             Registration Statement on Form 8-A filed with the Commission on
             October 30, 1997 (the "Form 8-A")).

4.3          Form of Right Certificate (incorporated by reference to Exhibit B
             to Exhibit 1 to the Form 8-A).

4.4          CD Radio Inc. 401(k) Savings Plan.

5.1          Opinion of Patrick L. Donnelly, Executive Vice President, General
             Counsel and Secretary of the Company, regarding the legality of the
             Common Stock being registered.

23.1         Consent of Patrick L. Donnelly, Executive Vice President,
             General Counsel and Secretary of the Company (included in
             Exhibit 5.1).

23.2         Consent of PriceWaterhouseCoopers LLP.
4

24.1         Power of Attorney (included on signature page).

ITEM 9.  UNDERTAKINGS

         (a) The undersigned registrant hereby undertakes: (i) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this registration statement to include any material information with respect
to the plan of distribution not previously disclosed in this registration
statement or any material change to such information in this registration
statement; (ii) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended, each such post-effective amendment 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; and (iii) 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, as amended, each
filing of the registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Securities Exchange Act of 1934, as amended, that is incorporated
by reference in this 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, as amended, may be permitted to directors, officers and
controlling persons of the registrant pursuant to the foregoing provisions, the
registrant's Amended and Restated Certificate of Incorporation or Amended and
Restated Bylaws, 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.
5

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
the registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York, on October 8, 1998.

                                                 CD RADIO INC.

                                                 By: /s/ Andrew J. Greenebaum
                                                 ----------------------------
                                                 Andrew J. Greenebaum
                                                 Executive Vice President and
                                                 Chief Financial Officer

         KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below hereby constitutes and appoints Andrew J. Greenebaum and Patrick
L. Donnelly, and each of them, his or her true and lawful agent, proxy and
attorney-in-fact, each acting alone with full power of substitution and
resubstitution, for him or her and in his or her name, place and sterad, in any
and all capacities, to (i) act on, sign and file with the Commission any and all
amendments (including post-effective amendments) to this registration statement
together with all schedules and exhibits thereto, (ii) act on, sign and file
such certificates, instruments, agreements and other documents as may be
necessary or appropriate in connection therewith, and (iii) take any and all
actions which may be necessary or appropriate in connection therewith, granting
unto such agents, proxies and attorneys-in-fact, and each of them, full power
and authority to do and perform each and every act and thing necessary or
appropriate to be done, as fully for all intents and purposes as he or she might
or could do in person, hereby approving, ratifying and confirming all that such
agents, proxies and attorneys-in-fact, any of them or any of his or her or their
substitutes may lawfully do or cause to be done by virtue thereof.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this registration statement has been signed by the following persons in the
capacities and on the dates indicated:

     Signatures                         Title                          Date
     ----------                         -----                          ----

/s/ David Margolese          Chairman and Chief Executive        October 8, 1998
------------------------     Officer (Principal Executive
David Margolese              Officer)
                             

/s/ Robert D. Briskman       Director                            October 8, 1998
------------------------
Robert D. Briskman
6

     Signatures                         Title                          Date
     ----------                         -----                          ----

/s/ Lawrence F. Gilberti     Director                            October 8, 1998
------------------------
Lawrence F. Gilberti                 

/s/ Joseph V. Vittoria       Director                            October 8, 1998
------------------------
Joseph V. Vittoria

/s/ Ralph W. Whitworth       Director                            October 8, 1998
------------------------
Ralph W. Whitworth

/s/Andrew J. Greenebaum      Executive Vice President and        October 8, 1998
------------------------     Chief Financial Officer
Andrew J. Greenebaum         (Principal Financial Officer)
                             

/s/ John T. McClain          Vice President and Controller       October 8, 1998
------------------------     (Principal Accounting Officer)
John T. McClain
7

                                INDEX TO EXHIBITS

Exhibits
--------

4.1          Form of Certificate for shares of Common Stock (incorporated by
             reference to Exhibit 4.3 to the Company's Registration Statement on
             Form S-1 (File No. 33- 74782) (the "S-1 Registration Statement")).

4.2          Rights Agreement, dated as of October 22, 1997, between the Company
             and Continental Stock Transfer & Trust Company, as Rights Agent
             (incorporated by reference to Exhibit 1 to the Company's
             Registration Statement on Form 8-A filed with the Commission on
             October 30, 1997 (the "Form 8-A")).

4.3          Form of Right Certificate (incorporated by reference to Exhibit B
             to Exhibit 1 to the Form 8-A).

4.4          CD Radio Inc. 401(k) Savings Plan.

5.1          Opinion of Patrick L. Donnelly, Executive Vice President, General
             Counsel and Secretary of the Company, regarding the legality of the
             Common Stock being registered (filed herewith).

23.1         Consent of Patrick L. Donnelly, Executive Vice President,
             General Counsel and Secretary of the Company (included in
             Exhibit 5.1).

23.2         Consent of PriceWaterhouseCoopers LLP.

24.1         Power of Attorney (included on signature page).