<PAGE>   1

     As filed with the Securities and Exchange Commission on August 31, 1998
                                              Registration No. 333-_____________

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

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

                                 WORLDCOM, INC.
             (Exact name of registrant as specified in its charter)

         GEORGIA                                            58-1521612
(State or other jurisdiction of                         (I.R.S. Employer
incorporation or organization)                          Identification No.)

                              515 EAST AMITE STREET
                         JACKSON, MISSISSIPPI 39201-2702
                          (Address, including zip code,
                  of registrant's principal executive offices)


   WORLDCOM, INC. 401(K) SALARY SAVINGS PLAN (F/K/A LDDS SALARY SAVINGS PLAN)
--------------------------------------------------------------------------------
                            (Full title of the plan)

                            P. BRUCE BORGHARDT, ESQ.
                                 WORLDCOM, INC.
                      10777 SUNSET OFFICE DRIVE, SUITE 330
                            ST. LOUIS, MISSOURI 63127
                                 (314) 909-4100
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
                         -------------------------------


                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>

-------------------------- ------------------------ ------------------------ ------------------------ ------------------------
                                                      Proposed maximum         Proposed maximum
 Title of securities to                               offering price per       aggregate offering     Amount of registration
    be registered(1)         Amount to be registered      share(2)                 price(2)                     fee
-------------------------- ------------------------ ------------------------ ------------------------ ------------------------
<S>                        <C>                      <C>                      <C>                      <C>
Common stock, $0.01 par           3,200,000
value, and associated             shares(4)                 $47.9688              $153,500,000                $45,283
preferred stock purchase
rights(3)
-------------------------- ------------------------ ------------------------ ------------------------ ------------------------
</TABLE>
----------

1      Pursuant to Rule 416(c) under the Securities Act of 1933, this
       registration statement also covers an indeterminate amount of interests
       to be offered or sold pursuant to the employee benefit plan described
       herein.

2      Computed pursuant to Rule 457(c) and Rule 457(h) solely for the purpose
       of determining the registration fee. Proposed maximum offering price
       represents the average of the high and low prices for the Registrant's
       Common Stock reported on the Nasdaq National Market on August 28, 1998.

3      Each share of Common Stock also represents one preferred stock purchase
       right. Preferred stock purchase rights cannot trade separately from the
       underlying common stock and, therefore, do not carry a separate price or
       necessitate an additional filing fee.

4      This Registration Statement also covers such additional shares of common
       stock as may be issuable pursuant to antidilution provisions.
<PAGE>   2


         This Registration Statement registers additional securities of the same
class as other securities for which a registration statement filed on this form
relating to the same employee benefit plan is effective. Consequently, pursuant
to General Instruction E of Form S-8, the contents of the Registration Statement
on Form S-8 filed by WorldCom, Inc. (the "Company") and the WorldCom, Inc.
401(k) Salary Savings Plan (f/k/a LDDS Salary Savings Plan) (the "Plan") on
November 9, 1993, Registration No. 33-71450, are incorporated by reference into
this Registration Statement.

Item 3.  Incorporation Of Certain Documents By Reference

         The following documents filed with the Securities and Exchange
Commission (the "Commission") by the Company (formerly Resurgens Communications
Group, Inc. ("Resurgens")) under File No. 0-11258 (formerly File No. 1-10415, in
the case of Resurgens) or by the WorldCom, Inc. 401(k) Salary Savings Plan (the
"Plan") under File No. 333-02115 pursuant to the Securities Exchange Act of
1934, as amended (the "Exchange Act"), are incorporated herein by reference and
shall be deemed to be a part hereof:

         (1) WorldCom's Annual Report on Form 10-K for the fiscal year ended
December 31, 1997;

         (2) WorldCom's Quarterly Reports on Form 10-Q for the quarterly periods
ended March 31, 1998 and June 30, 1998;

         (3) WorldCom's Current Reports on Form 8-K dated August 25, 1996 (filed
August 26, 1996, and as amended on Forms 8-K/A filed November 4, 1996, November
20, 1996, and December 19, 1997), November 9, 1997 (filed November 12, 1997, and
as amended on Forms 8-K/A-1 filed on January 27, 1998, on Form 8-K/A-2 filed on
January 28, 1998 and on Form 8-K/A-3 filed on May 28, 1998), January 29, 1998
(filed February 12, 1998), May 28, 1998 (filed May 28, 1998), July 23, 1998
(filed July 24, 1998), August 4, 1998 (filed August 4, 1998), August 6, 1998
(filed August 6, 1998) and August 6, 1998 (filed August 7, 1998);

         (4) the description of WorldCom's (formerly Resurgens') Common Stock as
contained in Item 1 of Resurgens' Registration Statement on Form 8-A dated
December 12, 1989, as updated by the descriptions contained in WorldCom's
Registration Statement on Form S-4 (File No. 333-16015), as declared effective
by the Commission on November 14, 1996, which includes the Joint Proxy
Statement/Prospectus dated November 14, 1996 with respect to WorldCom's Special
Meeting of Shareholders held on December 20, 1996, under the following captions:
"Description of WorldCom Capital Stock" and "Comparative Rights of
Shareholders";

         (5) the description of WorldCom's Preferred Stock Purchase Rights
contained in WorldCom's Registration Statement on Form 8-A dated August 26,
1996, as updated by WorldCom's Current Report on Form 8-K dated May 22, 1997
(filed June 6, 1997);

         (6) the description of the WorldCom Series B Convertible Preferred
Stock contained in WorldCom's Registration Statement on Form 8-A dated November
13, 1996; and

         (7) the Annual Report on Form 11-K of the Plan for the year ended
December 31, 1997.

         All documents filed by the Company or the Plan with the Commission
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act on or after
the date of this Registration Statement and prior to the termination of the
offering of the securities registered hereby shall be deemed to be incorporated
by reference herein and into the respective prospectus for the Plan and to be a
part hereof and thereof from the date of filing of such documents. Any statement
contained herein or therein or in a document incorporated or deemed to be
incorporated by reference herein or therein shall be deemed to be modified or
superseded for purposes of this Registration Statement to the extent that a
statement contained herein or therein or in any subsequently filed document
which also is or is deemed to be incorporated by reference herein or therein
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 or the prospectus.


                                       2
<PAGE>   3


Item 6.  Indemnification Of Directors And Officers

         Section 14-2-202(b)(4) of the Georgia Business Corporation Code (the
"Georgia Code") provides that a corporation's articles of incorporation may
include a provision that eliminates or limits the personal liability of
directors for monetary damages to the corporation or its shareholders for any
action taken, or any failure to take any action, as a director, provided,
however, that the Section does not permit a corporation to eliminate or limit
the liability of a director for appropriating, in violation of his or her
duties, any business opportunity of the corporation, for acts or omissions
including intentional misconduct or a knowing violation of law, receiving from
any transaction an improper personal benefit, or voting for or assenting to an
unlawful distribution (whether as a dividend, stock repurchase or redemption, or
otherwise) as provided in Section 14-2-832 of the Georgia Code. Section
14-2-202(b)(4) also does not eliminate or limit the rights of WorldCom or any
shareholder to seek an injunction or other nonmonetary relief in the event of a
breach of a director's duty to the corporation and its shareholders.
Additionally, Section 14-2-202(b)(4) applies only to claims against a director
arising out of his or her role as a director, and does not relieve a director
from liability arising from his or her role as an officer or in any other
capacity.

         The provisions of Article Ten of WorldCom's Second Amended and Restated
Articles of Incorporation are similar in all substantive respects to those
contained in Section 14-2-202(b)(4) of the Georgia Code as outlined above.
Article Ten further provides that the liability of directors of WorldCom shall
be limited to the fullest extent permitted by amendments to Georgia law.

         Sections 14-2-850 to 14-2-859, inclusive, of the Georgia Code govern
the indemnification of directors, officers, employees, and agents. Section
14-2-851 of the Georgia Code permits indemnification of a director of WorldCom
for liability incurred by him or her in connection with any threatened, pending
or completed action, suit or proceeding, whether civil, criminal, administrative
or investigative (including, subject to certain limitations, civil actions
brought as derivative actions by or in the right of WorldCom) in which he or she
is made a party by reason of being a director of WorldCom and of directors who,
at the request of WorldCom, act as directors, officers, partners, trustees,
employees or agents of another foreign or domestic corporation, partnership,
joint venture, trust, employee benefit plan or other enterprise. The Section
permits indemnification if the director acted in good faith and reasonably
believed (a) in the case of conduct in his or her official capacity, that such
conduct was in the best interests of the corporation, (b) in all other cases
other than a criminal proceeding that such conduct was at least not opposed to
the best interests of the corporation, and (c) in the case of a criminal
proceeding, that he or she had no reasonable cause to believe his or her conduct
was unlawful. If the required standard of conduct is met, indemnification may
include judgments, settlements, penalties, fines or reasonable expenses
(including attorneys' fees) incurred with respect to a proceeding.

         A Georgia corporation may not indemnify a director under Section
14-2-851 (i) in connection with a proceeding by or in the right of the
corporation, except for reasonable expenses incurred by such director in
connection with the proceeding provided it is determined that such director met
the relevant standard of conduct set forth above, or (ii) in connection with any
proceeding with respect to conduct for which such director was adjudged liable
on the basis that he or she received an improper personal benefit.

         Prior to indemnifying a director under Section 14-2-851 of the Georgia
Code, a determination must be made that the director has met the relevant
standard of conduct. Such determination must be made by: (i) a majority vote of
a quorum consisting of directors not at that time parties to the suit; (ii) a
duly designated committee of directors; (iii) duly selected special legal
counsel; or (iv) a vote of the shareholders, excluding shares owned by or voted
under the control of directors who are at the time parties to the suit.

         A Georgia corporation may, before final disposition of a proceeding,
advance funds to pay for or reimburse the reasonable expenses incurred by a
director who is a party to a proceeding because he or she is a director,
provided that such director delivers to the corporation a written affirmation of
his or her good faith belief that he or she met the relevant standard of conduct
described in Section 14-2-851 of the Georgia Code, or that the proceeding
involves conduct for which such director's liability has been properly
eliminated by action of the corporation, and a written undertaking by the
director to repay any funds advanced if it is ultimately determined that such
director was not entitled to such indemnification. Section 14-2-852 of the
Georgia Code provides that directors who are successful which respect to any
claim brought against them, which claim is brought because they are or were
directors of WorldCom, are entitled to mandatory indemnification against
reasonable expenses incurred in connection therewith.


                                       3
<PAGE>   4


         The Georgia Code also allows a Georgia corporation to indemnify
directors made a party to a proceeding without regard to the above-referenced
limitations, if authorized by the articles of incorporation or a bylaw,
contract, or resolution duly adopted by a vote of the shareholders of the
corporation by a majority of votes entitled to be cast, excluding shares owned
or voted under the control of the director or directors who are not
disinterested, and to advance funds to pay for or reimburse reasonable expenses
incurred in the defense thereof, subject to restrictions similar to the
restrictions described in the preceding paragraph; provided, however, that the
corporation may not indemnify a director adjudged liable (1) for any
appropriation, in violation of his or her duties, of any business opportunity of
WorldCom, (2) for acts or omissions which involve intentional misconduct or a
knowing violation of law, (3) for unlawful distributions under Section 14-2-832
of the Georgia Code, or (4) for any transaction in which the director obtained
an improper personal benefit.

         Section 14-2-857 of the Georgia Code provides that an officer of
WorldCom (but not an employee or agent generally) who is not a director has the
mandatory right of indemnification granted to directors under Section 14-2-852,
as described above. In addition, WorldCom may, as provided by WorldCom's Second
Amended and Restated Articles of Incorporation, WorldCom's Bylaws, general or
specific actions by its board of directors or contract, indemnify and advance
expenses to an officer, employee or agent who is not a director to the extent
that such indemnification is consistent with public policy.

         The indemnification provisions of Article X of WorldCom's Bylaws and
Article Eleven of WorldCom's Second Amended and Restated Articles of
Incorporation are consistent with the foregoing provisions of the Georgia Code.
However, WorldCom's Second Amended and Restated Articles of Incorporation
prohibit indemnification of a director who did not believe in good faith that
his or her actions were in, or not contrary to, WorldCom's best interests.
WorldCom's Bylaws extend the indemnification available to officers under the
Georgia Code to employees and agents.

Item 8.  Exhibits

         See Exhibit Index.

         The Registrant has submitted the plan and any amendment thereto to the
         Internal Revenue Service ("IRS") in a timely manner and has made or
         will make all changes required by the IRS in order to qualify the plan.


                                       4

<PAGE>   5




                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
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 Jackson, State of Mississippi on August 31, 1998.

                                                   WORLDCOM, INC.



                                                   By: /s/ Scott D. Sullivan
                                                       -----------------------
                                                       Scott D. Sullivan
                                                       Chief Financial Officer

                                POWER OF ATTORNEY

         Each person whose signature appears below hereby constitutes and
appoints Bernard J. Ebbers, Scott D. Sullivan, and P. Bruce Borghardt, and each
of them (with full power to each of them to act alone), his true and lawful
attorneys in fact and agents for him and on his behalf and in his 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 the same,
with exhibits and any and all other documents filed with respect thereto, with
the Securities and Exchange Commission (or any other governmental or regulatory
authority), granting unto said attorneys, and each of them, full power and
authority to do and to perform each and every act and thing requisite and
necessary to be done in and about the premises in order to effectuate the same
as fully to all intents and purposes as he himself might or could do if
personally present, hereby ratifying and confirming all that said attorneys in
fact and agents, or any of them, may lawfully do or cause to be done by virtue
hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>

             Name                                   Title                         Date
             ----                                   -----                         ----


<S>                                               <C>                        <C> 
/s/ James C. Allen                                 Director                   August 31, 1998
------------------------------------------
     James C. Allen



/s/ Carl J. Aycock                                 Director                   August 31, 1998
------------------------------------------
     Carl J. Aycock



/s/ Max E. Bobbitt                                 Director                   August 31, 1998
------------------------------------------
     Max E. Bobbitt

/s/ Stephen M. Case                                Director                   August 31, 1998
------------------------------------------
      Stephen M. Case


</TABLE>

                                       5
<PAGE>   6
<TABLE>
<CAPTION>
             Name                                   Title                         Date
             ----                                   -----                         ----


<S>                                               <C>                            <C> 
/s/ Bernard J. Ebbers                               Director, President and        August 31, 1998
--------------------------------------------        Chief Executive Officer
       Bernard J. Ebbers                            


/s/ Francesco Galesi                                Director                       August 31, 1998
--------------------------------------------
       Francesco Galesi



/s/ Stiles A. Kellett, Jr.                          Director                       August 31, 1998
--------------------------------------------
       Stiles A. Kellett, Jr.



/s/ John A. Porter                                  Director                       August 31, 1998
--------------------------------------------
       John A. Porter



/s/ John W. Sidgmore                                Director                       August 31, 1998 
--------------------------------------------        
       John W. Sidgmore                             
                                                                                                   
                                                                                                   
                                                                                                   
/s/ Scott D. Sullivan                               Director and Chief Financial   August 31, 1998 
--------------------------------------------        Officer (Principal Financial                   
       Scott D. Sullivan                            Officer and Principal                          
                                                    Accounting Officer)                            
                                                                                                   
                                                                                                   
/s/ Lawrence C. Tucker                              Director                       August 31, 1998 
--------------------------------------------                                                       
       Lawrence C. Tucker                                                                          
</TABLE>
                                       6

<PAGE>   7




         The Plan. Pursuant to the requirements of the Securities Act of 1933,
the Plan has duly caused this Registration Statement to be signed on its behalf
by the undersigned, thereunto duly authorized, in the City of Jackson, State of
Mississippi, on August 31, 1998.

                                    WORLDCOM, INC. 401(k) SALARY SAVINGS PLAN


                                    By:  /s/ Scott D. Sullivan
                                         -------------------------------------
                                             Scott D. Sullivan, Trustee

                                       7

<PAGE>   8


                                  EXHIBIT INDEX
<TABLE>
<CAPTION>

   EXHIBIT
    NUMBER              DESCRIPTION
   -------              -----------
   <S>         <C>
    23.1       Consent of Arthur Andersen LLP
    23.2       Consent of PricewaterhouseCoopers LLP
    23.3       Consent of Arthur Andersen LLP
    23.4       Consent of Arthur Andersen LLP
    23.5       Consent of PricewaterhouseCoopers LLP
    23.6       Consent of KPMG Peat Marwick LLP
    24.1       Power of Attorney (included in Signature Pages)
</TABLE>