
<PAGE>   1
      As filed with the Securities and Exchange Commission on June 1, 1999

                                                     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)

          CALIFORNIA                                      77-0059951
 (State or other jurisdiction                  (IRS Employer Identification No.)
of incorporation or organization)

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

                      FIBEX SYSTEMS 1997 STOCK OPTION PLAN
                            (Full title of the Plan)

                                JOHN T. CHAMBERS
                 PRESIDENT, CHIEF EXECUTIVE OFFICER AND DIRECTOR
                               CISCO SYSTEMS, INC.
             170 WEST 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>
====================================================================================================
                                                        Proposed           Proposed
            Title of                                    Maximum             Maximum
           Securities                  Amount           Offering           Aggregate      Amount of
              to be                    to be             Price             Offering      Registration
           Registered              Registered(1)      per Share(2)         Price (2)          Fee
           ----------              -------------      ------------         ---------     ------------
<S>                                <C>                <C>              <C>               <C>
 1997 STOCK OPTION PLAN
 Common Stock                      184,991 shares        $17.78        $3,289,139.98        $914.38
====================================================================================================
</TABLE>
(1)     This Registration Statement shall also cover any additional shares of
        Registrant's Common Stock which become issuable under the Fibex Systems
        1997 Stock Option Plan 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 Registrant's outstanding shares of 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.



<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 25, 1998 filed with the Commission on September 25,
                1998, pursuant to Section 13 of the Securities Exchange Act of
                1934, as amended (the "1934 Act").

        (b)     The Registrant's Current Reports on Form 8-K filed with the
                Commission on October 13, 1998, (for period date September 30,
                1998), November 20, 1998 (for period date November 2, 1998) and
                November 20, 1998 (for period date November 4, 1998) and May 14,
                1999 (for period date May 11, 1999).

        (c)     The Registrant's Quarterly Reports on Form 10-Q filed with the
                Commission on December 8, 1998 for the fiscal quarter ended
                October 24, 1998 and filed on March 9, 1999, as amended on May
                14, 1999, for the fiscal quarter ended January 23, 1999.

        (d)     The Registrant's Registration Statement No. 000-18225 on Form
                8-A filed with 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.

        (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.

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 Securities Act of 1933, as amended, (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



                                      II-1
<PAGE>   3
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 Statements 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-3 of this
                Registration Statement.
        99.1    Fibex Systems 1997 Stock Option Plan.
        99.2    Form of Notice of Stock Option Grant-Installment Option.
        99.3    Form of Stock Option Agreement-Installment Option.
        99.4    Form of Stock Option Agreement-Immediately Exercisable Option.
        99.5    Form of Exercise Notice and Restricted Stock Purchase
                Agreement-Installment Option.
        99.6    Form of Stock Option Exercise Agreement-Immediately Exercisable
                Option.
        99.7    Form of Stock 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
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 Fibex Systems 1997
Stock Option Plan.

                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-2
<PAGE>   4
                                   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
1st day of June, 1999.

                                            CISCO SYSTEMS, INC.


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

                                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           June 1, 1999
John T. Chambers           Office and Director
                           (Principal Executive Officer)


/s/ Larry R. Carter
------------------------   Senior Vice President, Finance        June 1, 1999
Larry R. Carter            and Administration, Chief Financial
                           Officer and Secretary
                           (Principal Financial and Accounting
                           Officer)

/s/ John P. Morgridge
------------------------   Chairman of the Board and             June 1, 1999
John P. Morgridge          Director



/s/ Donald T. Valentine
------------------------   Vice Chairman of the Board and        June 1, 1999
Donald T. Valentine        Director
</TABLE>



                                      II-3
<PAGE>   5

<TABLE>
<S>                        <C>                                   <C>

/s/ James F. Gibbons
------------------------   Director                              June 1, 1999
James F. Gibbons



/s/ Robert L. Puette
------------------------   Director                              June 1, 1999
Robert L. Puette




------------------------   Director                             June --, 1999
Masayoshi Son



/s/ Steven M. West
------------------------   Director                              June 1, 1999
Steven M. West



/s/ Edward R. Kozel
------------------------   Director                              June 1, 1999
Edward R. Kozel




------------------------   Director                             June --, 1999
Carol A. Bartz



/s/ James C. Morgan
------------------------   Director                              June 1, 1999
James C. Morgan



/s/ Mary Cirillo
------------------------   Director                              June 1, 1999
Mary Cirillo



/s/ Arun Sarin
------------------------   Director                              June 1, 1999
Arun Sarin
</TABLE>



                                      II-4
<PAGE>   6
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


                                    EXHIBITS

                                       TO

                                    FORM S-8

                                      UNDER

                             SECURITIES ACT OF 1933


                               CISCO SYSTEMS, INC.



<PAGE>   7
                                        EXHIBIT INDEX

<TABLE>
<CAPTION>
Exhibit Number  Exhibit
--------------  -------
<S>             <C>
        4       Instruments Defining the Rights of Stockholders. Reference is
                made to Registrant's Registration Statements 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-3 of this
                Registration Statement.
        99.1    Fibex Systems 1997 Stock Option Plan.
        99.2    Form of Notice of Stock Option Grant-Installment Option.
        99.3    Form of Stock Option Agreement-Installment Option.
        99.4    Form of Stock Option Agreement-Immediately Exercisable Option.
        99.5    Form of Exercise Notice and Restricted Stock Purchase
                Agreement-Installment Option.
        99.6    Form of Stock Option Exercise Agreement-Immediately Exercisable
                Option.
        99.7    Form of Stock Option Assumption Agreement.
</TABLE>



