
<PAGE>   1
    As filed with the Securities and Exchange Commission on January 24, 2001
                                                   Registration No. 333-________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933


                               CISCO SYSTEMS, INC.
             (Exact name of registrant as specified in its charter)
<TABLE>
<S>                                                      <C>
             CALIFORNIA                                            77-0059951
    (State or other jurisdiction                         (IRS Employer Identification No.)
  of incorporation or organization)
</TABLE>

                             170 WEST TASMAN DRIVE,
                         SAN JOSE, CALIFORNIA 95134-1706
               (Address of principal executive offices) (Zip Code)

             PIXSTREAM, INCORPORATED KEY EMPLOYEE STOCK OPTION PLAN
                       (AS ASSUMED BY CISCO SYSTEMS, INC.)


                            (Full title of the Plans)


                                JOHN T. CHAMBERS
                 PRESIDENT, CHIEF EXECUTIVE OFFICER AND DIRECTOR
                               CISCO SYSTEMS, INC.
                              300 EAST TASMAN DRIVE
                         SAN JOSE, CALIFORNIA 95134-1706
                     (Name and address of agent for service)
                                 (408) 526-4000
          (Telephone Number, including area code, of agent for service)

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
===================================================================================================================================
                                        Amount to be            Proposed Maximum            Proposed Maximum           Amount of
Title of Securities to be  Registered   Registered(1)        Offering Price per Share   Aggregate Offering Price    Registration Fee
-------------------------------------   -------------        ------------------------   ------------------------    ----------------
<S>                                     <C>                  <C>                        <C>                         <C>
PixStream, Incorporated Key
Employee Stock Option Plan
Common Stock, $0.001 par value            1,392,884 shares                                $     30,803,816.57(3)         $7,700.96
                                                                  $22.115(2)
===================================================================================================================================
</TABLE>

(1)  This Registration Statement shall also cover any additional shares of
     Common Stock which become issuable under the PixStream, Incorporated Key
     Employee Stock Option Plan (as assumed by Registrant) by reason of any
     stock dividend, stock split, recapitalization or other similar transaction
     effected without the Registrant's receipt of consideration which results in
     an increase in the number of the outstanding shares of Registrant's Common
     Stock.

(2)  Calculated solely for purposes of this offering under Rule 457(h) of the
     Securities Act of 1933, as amended, on the basis of the weighted average
     exercise price of the outstanding options, and rounded down to the nearest
     one tenth of one cent.

(3)  The actual aggregate offering price based on the actual weighted average
     exercise price per share.



<PAGE>   2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference

               Cisco Systems, Inc. (the "Registrant") hereby incorporates by
reference into this Registration Statement the following documents previously
filed with the Securities and Exchange Commission (the "Commission"):

        (a)    The Registrant's Annual Report on Form 10-K for the fiscal year
               ended July 29, 2000 filed with the Commission on September 29,
               2000, pursuant to Section 13 of the Securities Exchange Act of
               1934, as amended (the "1934 Act");

        (b)    The Registrant's Quarterly Report on Form 10-Q for the quarter
               ended October 28, 2000, filed with the Commission on December 12,
               2000;

        (c)    The Registrant's Current Reports on Form 8-K filed with the
               Commission on December 15, 1999 (as amended on Form 8-K/A filed
               with the Commission on February 3, 2000 and August 4, 2000),
               August 15, 2000, September 7, 2000, September 15, 2000, September
               26, 2000, September 28, 2000, September 29, 2000, November 6,
               2000, November 7, 2000, November 13, 2000, November 15, 2000,
               November 15, 2000, December 19, 2000, December 21, 2000 and
               December 27, 2000;

        (d)    The Registrant's Registration Statement No. 000-18225 on Form 8-A
               filed with the Commission on January 11, 1990, together with
               Amendment No. 1 on Form 8-A/A filed with the Commission on
               February 15, 1990, and including any other amendments or reports
               filed for the purpose of updating such description, in which
               there is described the terms, rights and provisions applicable to
               the Registrant's Common Stock, and;

        (e)    The Registrant's Registration Statement No. 000-18225 on Form 8-A
               filed with the Commission on June 11, 1998, including any
               amendments or reports filed for the purpose of updating such
               description, in which there is described the terms, rights and
               provisions applicable to the Registrant's Preferred Stock
               Purchase Rights.

               All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of
this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered hereby have been sold or
which de-registers all securities then remaining unsold shall be deemed to be
incorporated by reference into this Registration Statement and to be a 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 for purposes of this Registration Statement
to the extent that a statement contained herein or in any subsequently filed
document which also 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.

Item 4. Description of Securities

               Not applicable.

               With respect to securities to be offered to employees of the
Registrant's or Registrant's Israeli subsidiary, Cisco Systems Israel Limited,
which are subject to the securities laws of the State of Israel, the following
legend shall apply:

"THE SECURITIES AUTHORITY OF THE STATE OF ISRAEL HAS EXEMPTED CISCO SYSTEMS,
INC. FROM THE REQUIREMENT UNDER ISRAELI LAW TO OBTAIN A PERMIT WITH REGARD TO
THIS



                                      II-1
<PAGE>   3

FORM S-8. NOTHING IN THE EXEMPTION GRANTED SHALL BE CONSTRUED AS AUTHENTICATING
THE MATTERS CONTAINED IN THIS FORM S-8 OR AN APPROVAL OF THEIR RELIABILITY OR
ACCURACY OR AN EXPRESSION OF AN OPINION AS TO THE QUALITY OF THE SECURITIES
OFFERED HEREBY."


Item 5. Interests of Named Experts and Counsel

               Not applicable.

Item 6. Indemnification of Directors and Officers

               Section 317 of the California Corporations Code authorizes a
court to award, or a corporation's Board of Directors to grant indemnity to
directors and officers in terms sufficiently broad to permit indemnification
(including reimbursement of expenses incurred) under certain circumstances for
liabilities arising under the 1933 Act. The Registrant's Restated Articles of
Incorporation, as amended, and Amended and Restated Bylaws provide for
indemnification of its directors, officers, employees and other agents to the
maximum extent permitted by the California Corporations Code. In addition, the
Registrant has entered into Indemnification Agreements with each of its
directors and officers.

Item 7. Exemption from Registration Claimed

               Not applicable.

Item 8. Exhibits

<TABLE>
<CAPTION>
 Exhibit Number   Exhibit
 --------------   -------
<S>               <C>
       4          Instruments Defining the Rights of Stockholders.  Reference is made to
                  Registrant's Registration Statement No. 000-18225 on Form 8-A, together with
                  the amendments and exhibits thereto, which are incorporated herein by
                  reference pursuant to Items 3(d) and 3(e).
       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.
      23.1        Consent of PricewaterhouseCoopers LLP, Independent Accountants.
      23.2        Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.
      24          Power of Attorney.  Reference is made to page II-4 of this Registration
                  Statement.
      99.1        PixStream, Incorporated Key Employee Stock Option Plan.
      99.2        Form of PixStream, Incorporated Stock Option Plan Option Agreement.
      99.3        Form of PixStream Option Assumption Agreement.
</TABLE>

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 1933 Act, (ii) to reflect in the prospectus any facts
or events arising after the effective date of this 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 this
Registration Statement and (iii) 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; provided, however, that clauses (1)(i) and (1)(ii) shall
not apply if the information required to be included in a post-effective
amendment by those clauses is contained in periodic reports filed by the
Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act that are
incorporated by reference into this Registration Statement; (2) that for the
purpose of determining any liability under the 1933 Act 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



                                      II-2
<PAGE>   4
shall be deemed to be the initial bona fide offering thereof; and (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 PixStream,
Incorporated Key Employee Stock Option Plan (as assumed by Registrant).

               B. The undersigned Registrant hereby undertakes that, for
purposes of determining any liability under the 1933 Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
1934 Act that is incorporated by reference into 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
1933 Act may be permitted to directors, officers or controlling persons of the
Registrant pursuant to the indemnification provisions summarized in Item 6 or
otherwise, the Registrant has been advised that, in the opinion of the
Commission, such indemnification is against public policy as expressed in the
1933 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 1933 Act and
will be governed by the final adjudication of such issue.



                                      II-3
<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 San Jose, State of California on this
24th day of January, 2001.

                                        CISCO SYSTEMS, INC.



                                        By: /s/ John T. Chambers
                                           -------------------------------------
                                           John T. Chambers
                                           President, Chief Executive Officer
                                           and Director


                                POWER OF ATTORNEY

               KNOW ALL PERSONS BY THESE PRESENTS, that each person whose
signature appears below constitutes and appoints John T. Chambers and Larry R.
Carter, and each of them, as such person's true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution, for such person and
in such person's name, place and stead, in any and all capacities, to sign any
and all amendments (including post-effective amendments) to this Registration
Statement, and to file same, with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorneys-in-fact and agents, and each of them, full power and authority to
do and perform each and every act and thing requisite and necessary to be done
in connection therewith, as fully to all intents and purposes as such person
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his or her
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 below by the following
persons on behalf of the Registrant and in the capacities and on the dates
indicated:

<TABLE>
<CAPTION>
           SIGNATURE                               TITLE                                  DATE
           ---------                               -----                                  ----
<S>                                <C>                                             <C>
/s/ John T. Chambers               President, Chief Executive Officer              January 24, 2001
-----------------------------      and Director (Principal Executive
John T. Chambers                   Officer)

/s/ Larry R. Carter                Senior Vice President, Finance and              January 24, 2001
-----------------------------      Administration, Chief Financial Officer,
Larry R. Carter                    Secretary and Director (Principal Financial
                                   and Accounting Officer)

/s/ John P. Morgridge              Chairman of the Board and Director              January 24, 2001
-----------------------------
John P. Morgridge
</TABLE>



                                      II-4
<PAGE>   6

<TABLE>
<CAPTION>
           SIGNATURE                               TITLE                                  DATE
           ---------                               -----                                  ----
<S>                                <C>                                             <C>
/s/ Donald T. Valentine            Vice Chairman of the Board and                  January 24, 2001
-------------------------------    Director
Donald T. Valentine

/s/ James F. Gibbons               Director                                        January 24, 2001
-----------------------------
James F. Gibbons

/s/ Steven M. West                 Director                                        January 24, 2001
-----------------------------
Steven M. West

/s/ Edward R. Kozel                Director                                        January 24, 2001
-----------------------------
Edward R. Kozel

/s/ Carol A. Bartz                 Director                                        January 24, 2001
-----------------------------
Carol A. Bartz

/s/ James C. Morgan                Director                                        January 24, 2001
-----------------------------
James C. Morgan

/s/ Mary Cirillo                   Director                                        January 24, 2001
-----------------------------
Mary Cirillo

/s/ Arun Sarin                     Director                                        January 24, 2001
-----------------------------
Arun Sarin

/s/ Jerry Yang                     Director                                        January 24, 2001
-----------------------------
Jerry Yang

/s/ Carly Fiorina                  Director                                        January 24, 2001
-----------------------------
Carly Fiorina
</TABLE>



                                      II-5
<PAGE>   7

                       SECURITIES AND EXCHANGE COMMISSION

                                WASHINGTON, D.C.


                                    EXHIBITS

                                       TO

                                    FORM S-8

                                      UNDER

                             SECURITIES ACT OF 1933


                               CISCO SYSTEMS, INC.



<PAGE>   8

                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
 Exhibit Number   Exhibit
 --------------   -------
 <S>              <C>
       4          Instruments Defining the Rights of Stockholders.  Reference is made to
                  Registrant's Registration Statement No. 000-18225 on Form 8-A, together with
                  the amendments and exhibits thereto, which are incorporated herein by
                  reference pursuant to Items 3(d) and 3(e).
       5          Opinion and consent of Brobeck, Phleger & Harrison LLP.
      23.1        Consent of PricewaterhouseCoopers LLP, Independent Accountants.
      23.2        Consent of Brobeck, Phleger & Harrison LLP is contained in Exhibit 5.
      24          Power of Attorney.  Reference is made to page II-4 of this Registration
                  Statement.
      99.1        PixStream, Incorporated Key Employee Stock Option Plan.
      99.2        Form of PixStream, Incorporated Stock Option Plan Option Agreement.
      99.3        Form of PixStream Option Assumption Agreement.
</TABLE>



