<PAGE>   1
 
================================================================================
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                                  FORM 10-K/A
                ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                      THE SECURITIES EXCHANGE ACT OF 1934
 
FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997        COMMISSION FILE NUMBER 1-4115
 
                         ZENITH ELECTRONICS CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
<TABLE>
<S>                                                <C>
                  DELAWARE                                          36-1996520
      (STATE OR OTHER JURISDICTION OF                (I.R.S. EMPLOYER IDENTIFICATION NUMBER)
       INCORPORATION OR ORGANIZATION)
 1000 MILWAUKEE AVENUE, GLENVIEW, ILLINOIS                          60025-2493
  (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                          (ZIP CODE)
</TABLE>
 
       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE (847) 391-7000
 
          SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:
 
<TABLE>
<CAPTION>
                                                                  NAME OF EACH EXCHANGE
                    TITLE OF EACH CLASS                            ON WHICH REGISTERED
                    -------------------                           ---------------------
<S>                                                             <C>
COMMON STOCK, $1 PAR VALUE AND ASSOCIATED PURCHASE RIGHTS       NEW YORK STOCK EXCHANGE
                                                                CHICAGO STOCK EXCHANGE
                                                                BASEL, GENEVA AND ZURICH,
                                                                SWITZERLAND STOCK EXCHANGE
6 1/4% CONVERTIBLE SUBORDINATED DEBENTURES, DUE 2011            NEW YORK STOCK EXCHANGE
</TABLE>
 
          SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:
 
                                      NONE
 
INDICATE BY CHECK MARK IF DISCLOSURE OF DELINQUENT FILERS PURSUANT TO ITEM 405
OF REGULATION S-K IS NOT CONTAINED HEREIN, AND WILL NOT BE CONTAINED, TO THE
BEST OF REGISTRANT'S KNOWLEDGE, IN DEFINITIVE PROXY STATEMENTS INCORPORATED BY
REFERENCE IN PART III OF THIS FORM 10-K OR ANY AMENDMENT TO THIS FORM 10-K.  [X]
 
INDICATE BY CHECK MARK WHETHER THE REGISTRANT (1) HAS FILED ALL REPORTS REQUIRED
TO BE FILED OF THE SECURITIES EXCHANGE ACT OF 1934 DURING THE PRECEDING 12
MONTHS (OR FOR SUCH SHORTER PERIOD THAT THE REGISTRANT WAS REQUIRED TO FILE SUCH
REPORTS), AND (2) HAS BEEN SUBJECT TO SUCH FILING REQUIREMENTS FOR THE PAST 90
DAYS.  YES [X]  NO [ ]
 
THE AGGREGATE MARKET VALUE OF THE REGISTRANT'S COMMON STOCK HELD BY
NON-AFFILIATES BASED ON THE NEW YORK STOCK EXCHANGE CLOSING PRICE ON MARCH 18,
1998, WAS $220,564,685.
 
AS OF MARCH 18, 1998, THERE WERE 67,525,447 SHARES OF COMMON STOCK, PAR VALUE $1
PER SHARE OUTSTANDING.
 
================================================================================
<PAGE>   2
 
                                    PART III
 
ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
 
<TABLE>
<CAPTION>
                                       DIRECTOR
NAME                             AGE    SINCE     BACKGROUND INFORMATION
----                             ---   --------   ----------------------
<S>                              <C>   <C>        <C>
T. Kimball Brooker.............  58      1989     President, Barbara Oil Company (investments and oil
                                                  and gas exploration) since 1989; Managing Director,
                                                  Chicago Office, Morgan Stanley & Co. Incorporated,
                                                  1978-1988. Also Director of Cutler Oil & Gas
                                                  Corporation, Arthur J. Gallagher & Co. and Miami
                                                  Corporation.
Ki-Song-Cho....................  48      1995     Managing Director, Overseas Sales of Display Division
                                                  of LG Electronics Inc. since December, 1997. Managing
                                                  Director, President of North America Operation from
                                                  November 1996 to December 1997; Managing Director,
                                                  Corporate Planning & Coordination, LG Electronics
                                                  Inc. from March 1995 to October 1996; Executive
                                                  Director, Strategic Planning Division, LG Electronics
                                                  Inc. from 1992 to 1995; Employed by the Strategic
                                                  Planning Division, LG Electronics Inc. from 1989 to
                                                  1992.
Eugene B. Connolly.............  66      1995     Chairman Emeritus of USG Corporation and employed in
                                                  varying capacities with USG Corporation and its
                                                  affiliates since 1958; also Director, U.S. Can
                                                  Corporation, the Pepper Companies, Inc. and LaSalle
                                                  National Bank; Advisory Board member of Good Shepherd
                                                  Hospital, Kellogg Graduate School of Management,
                                                  Northwestern University and Indiana University School
                                                  of Business.
Robert A. Helman...............  64      1996     Partner in the law firm of Mayer, Brown & Platt since
                                                  1967; also Director, Northern Trust Corporation,
                                                  Dreyer's Grand Ice Cream, Inc. and The Chicago Stock
                                                  Exchange.
Cha Hong (John) Koo............  51      1995     Vice Chairman of Zenith Electronics Corporation;
                                                  Director, President and CEO of LG Electronics Inc.
                                                  since 1996; Executive Vice President from 1991 to
                                                  1994; Senior Managing Director from 1988 to 1991.
Seung Pyeong Koo...............  55      1997     Director and Executive Vice President of LG
                                                  Electronics Inc. since 1996; President of Display
                                                  Division since 1992; Senior Managing, Director from
                                                  1995 to 1996; Managing Director from 1991 to 1995,
                                                  Vice President of TV Display Division 1990 to 1992.
Hun Jo Lee.....................  65      1995     Chairman of the Board, Zenith Electronics Corporation
                                                  since 1996; Chairman of LG Academy since February
                                                  1996; Director and former Chairman and Chief
                                                  Executive Officer of LG Electronics Inc. from 1994 to
                                                  1996; Vice Chairman and Chief Executive Officer from
                                                  1993 to 1994; President and Chief Executive Officer
                                                  from 1989 to 1993.
Andrew McNally IV..............  58      1990     Managing Director of Hammond, Kennedy, Whitney &
                                                  Company, Inc. (private equity investments). Former
                                                  Chairman and Chief Executive Officer and current
                                                  Director of Rand McNally (printing, publishing and
                                                  map making); Director of Hubbell, Incorporated,
                                                  Mercury Finance Company, Borg-Warner Securities
                                                  Corporation and Morgan Stanley Funds.
</TABLE>
 
                                        2
<PAGE>   3
 
<TABLE>
<CAPTION>
                                       DIRECTOR
NAME                             AGE    SINCE     BACKGROUND INFORMATION
----                             ---   --------   ----------------------
<S>                              <C>   <C>        <C>
Yong Nam.......................  49      1995     Executive Vice President of LG Electronics Inc. and
                                                  President of Multi-media Division since December
                                                  1997; Executive Vice President of LG Group Chairman's
                                                  Office from January, 1997 to December 1997; Senior
                                                  Managing Director from 1995 to January 1997; Managing
                                                  Director from 1993 to 1995.
Peter S. Willmott..............  60      1990     President and Chief Executive Officer of Zenith
                                                  Electronics Corporation from July, 1997 to January,
                                                  1998; Chairman and Chief Executive Officer, Willmott
                                                  Services, Inc. (retailing, consulting and investing)
                                                  since 1989; Chairman, President and Chief Executive
                                                  Officer, Carson Pirie Scott & Company (retail and
                                                  food services industries), 1983-1989; Director of
                                                  Federal Express Corporation and Security Capital
                                                  Group, Inc.
Nam Woo........................  49      1997     President of North American Operations of LG
                                                  Electronics Inc. since January, 1998; Senior Managing
                                                  Director of LG Electronics Inc. since February 1997;
                                                  Corporate planning and coordination of LG Electronics
                                                  Inc. from November 1996 to October 1997; Senior
                                                  Managing Director since February, 1997; President of
                                                  LG Electronics U.S.A. Inc. & North American
                                                  Operations from February 1995 to November 1997;
                                                  President of European Operations of LG Electronics
                                                  Inc. from 1994 to 1995; Elected as a Managing
                                                  Director of LG Electronics Inc. in February 1994.
                                                  </TABLE>
 
     Mr. Helman is a partner in the law firm of Mayer, Brown & Platt which from
time to time has provided in the past and may continue to provide, legal
services to the Company and its subsidiaries. Mayer, Brown & Platt also provides
legal services to LGE. Messrs. Cho, John Koo, S.P. Koo, Lee, Nam and Woo are
employees of LGE, which with Semicon, collectively own approximately 56.5% of
the Company's stock. LGE has been in the past and is expected to continue to be
a significant customer and supplier of the Company. (See Footnote Six--"Related
Party"--Notes to Consolidated Financial Statements). USG Corporation, of which
Mr. Connolly was formerly the Chairman and Chief Executive Officer, implemented
a "prepackaged" plan of reorganization under the federal bankruptcy laws on May
6, 1993.
 
            BOARD AND COMMITTEE MEETINGS AND DIRECTORS' COMPENSATION
 
     To permit the Board of the Company to more efficiently discharge its
duties, the Company has four standing Board Committees: the Executive Committee,
the Audit Committee, the Organization and Compensation Committee and the Stock
Compensation Committee.
 
     Committee membership and functions are set out below. The Company does not
have a nominating committee.
 
     The Executive Committee, which currently consists of Messrs. Nam
(Chairman), Brooker, Connolly, Helman, McNally and Willmott, met three times in
1997. When the Board is not in session, the Executive Committee has all of the
authority of the Board except with respect to certain matters such as amendments
of the Restated Certificate of Incorporation or By-Laws, mergers, dispositions
of substantially all of the assets of the Company, dissolution of the Company,
declaration of dividends or the election, compensation or removal of officers of
the Company or members of the Committee.
 
     The Audit Committee of the Board of Directors, which currently consists of
Messrs. McNally (Chairman), Brooker and Connolly, met six times in 1997. The
Committee nominates the Company's independent auditors, reviews the auditing
engagement, the fees charged by the independent auditors and the Company's
internal auditing program. The Committee also reviews and monitors significant
transactions
 
                                        3
<PAGE>   4
 
between the Company and LGE. In 1997, of the six meetings held by the Audit
Committee two were special meetings in which the Audit Committee acted as a
finance committee to consider various financing alternatives for the Company.
 
     The Organization and Compensation Committee, which currently consists of
Messrs. Connolly (Chairman), Helman and McNally, met three times in 1997. The
Committee establishes compensation policies, as well as salary ranges, salaries
and annual incentive awards for executives and approves employment contracts.
The Stock Compensation Committee, which currently consists of Messrs. Connolly
and McNally, authorizes grants of stock, stock options and other equity-based
awards under the Long-Term Equity Compensation Plan. The Organization and
Compensation Committee met three times in 1997.
 
     The Company's Board of Directors met six times during 1997. With the
exception of Mr. Cho who was absent from two board meetings, all of the
incumbent directors attended at least 75% of the meetings of the Board and of
the Committees of which they were members.
 
     Directors of the Company who are also employees of the Company, of LGE or
its affiliates receive no remuneration for serving on the Board or on any
Committees. Other directors are compensated at the rate of $18,000 per year,
payable in quarterly installments. The Chairman of the Audit Committee and the
Chairman of the Organization and Compensation Committee each receives $2,000
annually for serving in those capacities. In addition, directors who are not
employees of the Company, LGE or its affiliates receive $1,000 for each Board
meeting and for each Committee meeting attended. All directors are entitled to
be reimbursed for their expenses for attending Board or Committee meetings.
Under the terms of the Company's Long-Term Equity Compensation Plan, approved by
the stockholders in May, 1997, directors are eligible to receive awards of stock
options, stock appreciation rights, restricted stock and performance
units/shares. Messrs. Brooker, Connolly, Helman and McNally were each granted an
option to purchase 2,000 shares of Company stock on July 18, 1997, at the market
price of the Company stock on that date. In 1987 the Company adopted a
Contingent Compensation Plan for non-employee directors. The number of phantom
stock appreciation units granted to each named non-employee director in previous
years under the Contingent Compensation Plan (all of which are vested) are as
follows: Mr. Brooker, 3,000; Messrs. McNally and Willmott, 2,000. The units are
valued at the closing price of the Company's common stock on the date of grant.
Participants are paid for each unit the amount by which the average price of a
share of the Company's common stock over the 20 trading days immediately
preceding the distribution date exceeds the grant price. Distributions may be,
at the election of the participant, in a lump sum, in five annual installments
or ten annual installments commencing on the distribution date. Participants may
elect a distribution date which is two years from the date of grant, or 30 days
after the participant ceases to be a director, or a specified date not earlier
than the participant's 65th birthday. Except for $143.75 distributed to Mr.
McNally in exchange for 1,000 units, no amounts have been distributed to current
directors pursuant to the Contingent Compensation Plan.
 
     Directors who are not employees of the Company, LGE or its affiliates
participate in the Directors' Retirement Plan which provides for an annual
retirement benefit of $11,000 for such directors who have served on the Board
for five years and who retire after the age of 62. For purposes of the
Directors' Retirement Plan, years of service on the Board do not include periods
during which the director is a salaried officer of the Company or a subsidiary.
The benefit is payable in equal quarterly installments during the director's
lifetime for a period equal to but not in excess of the number of years of
service on the Board. In the event of a change in control of the Company,
directors not continuing after a change in control but otherwise entitled to
retirement benefits under the Directors' Retirement Plan are entitled to
receive, in a lump sum, the discounted present value of those benefits.
 
ITEM 11.  EXECUTIVE COMPENSATION
 
                  EXECUTIVE COMPENSATION AND OTHER INFORMATION
 
     The following Summary Compensation Table sets forth, for the periods
indicated, the cash compensation and certain other components of compensation of
those persons who were, at December 31, 1997, the chief executive officer of the
Company and the other four most highly compensated executive officers of the
                                        4
<PAGE>   5
 
Company. The table includes the former Chief Executive Officer of the Company,
Peter S. Willmott, who left the Company in January, 1998, and two former
executive officers of the Company, Ramesh Amin and Dennis Winkleman, who left
the Company in 1997, whose compensation would have placed them in the group of
the four other most highly compensated officers of the Company had they been
executive officers as of December 31, 1997. Those listed in the table are
hereinafter referred to as the "Named Executive Officers."
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                                                SECURITIES
                                                                                                UNDERLYING
   NAME AND PRINCIPAL             SALARY     BONUS        OTHER ANNUAL       RESTRICTED STOCK    OPTIONS/        ALL OTHER
        POSITION           YEAR     ($)       ($)     COMPENSATIONS($)(1)     AWARDS ($)(2)      SARS (#)    COMPENSATION($)(3)
-------------------------  ----   -------   -------   --------------------   ----------------   ----------   ------------------
<S>                        <C>    <C>       <C>       <C>                    <C>                <C>          <C>
Peter S. Willmott........  1997   775,000         0            0                1,612,500        100,000            4,800
Former President and       1996   539,192         0            0                        0          2,000                0
Chief Executive Officer    1995         0         0            0                        0          2,000                0
Michael Ahn..............  1997   337,992         0            0                        0              0                0
Former Senior              1996   118,040         0            0                        0              0                0
Vice President             1995         0         0            0                        0              0                0
Ramesh G. Amin...........  1997   333,340   200,000            0                        0         60,000          329,381(5)
Former Executive           1996    25,000   120,000(4)         0                        0              0                0
Vice President             1995         0         0            0                        0              0                0
Roger A. Cregg...........  1997   300,000    37,500            0                        0         35,000            6,682
Former Executive           1996   190,909   150,000(4)         0                  525,000         37,500                0
Vice President and         1995         0         0            0                        0              0                0
Chief Financial Officer
Richard F. Vitkus........  1997   229,999    23,000            0                        0         25,000            9,600
Senior Vice President,     1996   218,333    14,000            0                  420,000         30,000            9,000
General Counsel and        1995   191,000    60,000(4)         0                        0         22,500            4,335
Secretary
Dennis R. Winkleman......  1997   130,004    15,000            0                        0         25,000                0
Former Vice President      1996   118,750     8,500(4)         0                        0         35,000                0
                           1995         0         0            0                        0              0                0
</TABLE>
 
---------------
 
(1)  Other Annual Compensation does not reflect the value of perquisites and
     other personal benefits since such compensation does not exceed minimum
     disclosure thresholds.
 
(2)  The share unit and restricted stock values shown in the table are based on
     the closing price of the Company's common stock on the date of grant. As of
     December 31, 1997, Mr. Cregg held an aggregate of 37,500 shares of
     restricted stock valued at $203,887, Mr. Vitkus held an aggregate of 30,000
     shares of restricted stock valued at $163,110 and Mr. Willmott held an
     aggregate of 37,500 share units valued at $203,887. Mr. Cregg's restricted
     stock was not vested when he left the Company, and, therefore, the
     restricted stock was forfeited. Mr. Willmott's share units were forfeited
     as part of his negotiated separation payment. See "Employment Agreements".
 
(3)  The amount reflects the annual contribution to the Company's defined
     contribution plan for Messrs. Cregg, Vitkus and Willmott. Since Messrs.
     Cregg and Willmott were not fully vested at the time of their termination
     of employment, the Company contributions were forfeited.
 
(4)  Pursuant to separate agreements, Messrs. Amin, Cregg, Vitkus and Winkleman
     were guaranteed bonuses relating to their initial employment.
 
(5) In connection with Mr. Amin's termination of employment with the Company, he
     entered into a Termination Agreement which provides for severance payments
     in lieu of those set forth in his employment agreement. The amount
     represents 1997 payments of $15,384 of accrued vacation pay, severance pay
     of $66,667, $2,834 of imputed income for Company paid term life insurance
     premiums, $102,500 for loss on sale of residence, $105,190 tax gross-up for
     relocation related expenses and $36,806 for relocation expenses. The
     Termination Agreement provides for three 1998 severance payments of
 
                                        5
<PAGE>   6
 
     $200,000 each, payable on January 1, 1998, March 1, 1998 and June 1, 1998.
     Mr. Amin is also entitled to outplacement service not to exceed $25,000 and
     continued group health benefits until the earlier of December 31, 1998, or
     the date when Mr. Amin becomes covered under another health benefit plan.
 
                             EMPLOYMENT AGREEMENTS
 
     The only Named Executive Officer who is currently an employee of the
Company is Mr. Vitkus who has a three year employment agreement which was
effective on January 1, 1997 and which expires on December 31, 1999. The
employment period is automatically extended for additional one year periods
unless the Company elects not to extend the agreements by giving 90 days written
notice prior to the end of any such period.
 
     The above mentioned employment agreement also provides a death benefit in
the amount of one and one-half times the individual's salary. The death benefit
is provided during the period of employment and for a period of ten years
thereafter. At the end of each of the ten years following the termination of
employment, the amount of death benefit decreases by ten percent of the original
amount. The agreement also provides supplemental long-term disability benefits
in the amount of two-thirds of the amount by which the individual's base salary
exceeds the maximum insured salary under the Company's long-term disability
program. The supplemental long-term disability benefits are currently limited to
$60,000 per year. The employment agreement described above provides that the
Company will pay to the employee, pursuant to the employment agreement, the
amount by which the benefits payable under the Company's retirement plan
("Zenith Salaried Retirement Savings Plan") exceed the benefit limitations
imposed by the Employee Retirement Income Security Act or the Internal Revenue
Code. This latter benefit is incorporated into the Zenith Electronics
Corporation Supplemental Salaried Profit Sharing Retirement Plan.
 
     Upon either a non-renewal of the employment agreement by the Company or
upon termination of employment other than for death, disability, retirement, or
by the Company for cause, the above Named Executive Officer will be entitled to
receive (a) a lump sum severance payment equal to the greater of (i) the sum of
the above Named Executive Officer's base compensation and target bonus,
multiplied by the number of whole and/or fractional years remaining under the
employment agreement, and (ii) one and one-half times the sum of the above Named
Executive Officer's base compensation and target bonus for the year in which
termination occurs; (b) continued coverage, or substantially equivalent
coverage, (for either one and one-half years or the remaining term under the
employment agreement), under all welfare plans including group medical and
dental, health and accident, long-term disability, short-term disability, group
life insurance and executive insurance in which the above Named Executive
Officer was participating at the time of his termination (if the Company is
unable to provide such continued coverage or substantially similar coverage, the
Company will pay the above Named Executive Officer a lump sum cash amount equal
to the present value of such benefits); and (c) outplacement services not to
exceed 15% of the above Named Executive Officer's base compensation.
 
     Upon termination of employment of the above Named Executive Officer within
two years after a change in control of the Company ("Change in Control Period"),
the employment agreement provides for severance pay and benefits (change in
control is defined in the employment agreement; the definition excludes any
further acquisition by LGE.) During the Change in Control Period, severance pay
and benefits will not be paid if employment is terminated because of death,
disability or retirement, or by the Company for cause, or by the above Named
Executive Officer other than for good reason. The employment agreement provides
for a lump sum payment equal to three times the highest annual base compensation
during the three full fiscal years prior to termination, plus three times the
greater of (i) the highest annual bonus payable during the three full fiscal
years prior to termination and (ii) the target bonus payable for the year in
which termination occurs. Other provisions of the employment agreement require
the Company to maintain for the benefit of the above Named Executive Officer for
a period of three years after his termination, all employee benefits including
group medical and dental, health and accident, long term disability and group
life insurance in which the above Named Executive Officer was participating at
the time of his termination. If the Company is unable to provide such continued
coverage or substantially similar coverage, the Company will pay the above Named
Executive
 
                                        6
<PAGE>   7
 
Officer a lump sum cash amount equal to the present value of such benefits. The
Company shall pay for outplacement services not to exceed 15% of the above Named
Executive Officer's base compensation. The employment agreement further provides
for payment of an amount sufficient to put him in the same after-tax position as
if no excise taxes imposed by Section 4999 of the Internal Revenue Code had been
imposed on any payments which are contingent on a change in control and which
equal or exceed three times the average taxable compensation for the prior five
years or their period of employment. The Company is obligated to reimburse the
above Named Executive Officer for legal fees and expenses incurred in
successfully enforcing the employment agreement.
 
     The Named Executive Officer participates in the Performance Optimization
Plan (POP). POP provides a cash payment in an amount equal to three times the
Named Executive Officer's base salary and target bonus in effect as of December
31, 1999 if (a) the aggregate pre-tax earnings during the years 1997, 1998 and
1999 equal or exceed an amount equal to break-even (zero earnings), after taking
into account the gross pre-tax cost to the Company of making the payments to the
executives selected for POP and (b) the Named Executive Officer is employed by
the Company on December 31, 1999. If the aggregate earnings for these three
years falls below zero, no payment will be made and the POP will terminate.
 
     Mr. Willmott, former President and Chief Executive Officer, terminated his
employment with the Company in January, 1998. His employment agreement provided
that in the event of his termination of employment other than for death,
disability or by the Company for cause, or by Mr. Willmott, he would be entitled
to receive (a) his salary through December 29, 1998, (b) a payment in lieu of
bonus based on actual performance (subject to a $450,000 minimum), (c) a cash
payment equal to the fair market value of the share units credited to his Stock
Account, and (d) a cash payment equal to the amount which would have been
allocated to his accounts under the Zenith Salaried Retirement Savings Plan
and/or the Zenith Electronics Corporation Supplemental Salaried Profit Sharing
Retirement Plan determined as though he had been employed through December 31,
1998. Also all unexercised stock options, whether vested or not, would be
exercisable for a three year period expiring on the third anniversary of the
termination date. The Company and Mr. Willmott agreed to a separation payment
of $500,000 in lieu of the termination benefits agreed to provided for in his 
employment agreement.
 
                       LONG-TERM EQUITY COMPENSATION PLAN
 
     On May 22, 1997, the stockholders approved adoption of the Zenith
Electronics Corporation Long-Term Equity Compensation Plan (the "Equity Plan").
Under the Equity Plan, participants may be granted stock options, stock
appreciation rights, restricted stock and performance units/shares. Performance
units/shares are awards granted in terms of a stated potential maximum number of
units or shares, with the actual number and value earned to be determined by
reference to the level of achievement of corporate, group, division, individual
or other specific objectives over a specified performance period. If shares of
restricted stock are issued pursuant to an award, the participant may have the
right to vote the shares and receive dividends thereon from the date of
issuance, unless and until forfeited. If performance shares are earned pursuant
to an award, amounts equal to the dividends payable on a like number of shares
of common stock may, if the award so provides, either be paid to the participant
or credited to his account and held until the award is forfeited or paid out.
 
     Stock options granted under the Equity Plan may either be "incentive stock
options" as defined in the Internal Revenue Code of 1986 (the "Code") or
non-qualified stock options. No option shall be exercisable more than ten years
after the date of grant. The per share option price shall not be less than 100%
of the fair market value at the time the option is granted. Upon exercise, the
option price and, if the Board or any Committee requires, any withholding tax
required by law, may be paid in cash, or, with the approval of the Board or any
Committee, in shares of the Company's common stock having a fair market value
equal to the option price and/or the amount of the withholding tax, or a
combination of cash and common stock.
 
     Stock appreciation rights granted under the Equity Plan entitle the grantee
to receive in the discretion of the Board or any Committee cash or shares of
common stock of the Company having a fair market value equal to the appreciation
in market value from the date of the grant of a stated number of shares of
common stock.
                                        7
<PAGE>   8
 
Stock appreciation rights under the Equity Plan may be granted in tandem with a
related stock option or independently. If a stock appreciation right is granted
in tandem with a stock option, the grantee may exercise either the stock option
or the stock appreciation right, but not both. Stock appreciation rights are not
exercisable more than ten years from the date of grant.
 
     The Board of Directors may amend or terminate the Equity Plan at any time,
except that no amendment or termination may be made which will adversely affect
in a material way any award previously granted under the Equity Plan, without
the written consent of the applicable participant.
 
                           OPTION/SAR GRANTS IN 1997
 
     Shown below is information regarding 1997 grants of stock options to the
Named Executive Officers. No stock appreciation rights (SARs) were granted to
the Named Executive Officers during 1997.
 
<TABLE>
<CAPTION>
                          NUMBER OF SECURITIES
                               UNDERLYING          PERCENT OF TOTAL     EXERCISE OR                  GRANT DATE
                              OPTIONS/SARS       OPTIONS/SARS GRANTED    BASE PRICE    EXPIRATION     PRESENT
          NAME               GRANTED (#)(1)      TO EMPLOYEES IN 1997   ($/SHARE)(2)      DATE      VALUE ($)(3)
          ----            --------------------   --------------------   ------------   ----------   ------------
<S>                       <C>                    <C>                    <C>            <C>          <C>
Peter S. Willmott.......        100,000                 10.5%              $11.00        1/2/07       $916,000
Michael Ahn.............              0                    0%                   0             0       $      0
Ramesh G. Amin..........         60,000                  6.3%              $11.25       4/22/07       $558,600
Roger A. Cregg..........         35,000                  3.6%              $11.25       4/22/07       $325,850
Richard F. Vitkus.......         25,000                  2.6%              $11.25       4/22/07       $232,750
Dennis R. Winkleman.....         25,000                  2.6%              $11.25       4/22/07       $232,750
</TABLE>
 
---------------
 
(1) Except for Mr. Willmott, all options granted and reported in this table have
     the following terms: each option vests over a three-year period, with
     one-third of the shares each becoming exercisable on the first, second and
     third anniversary after the date of grant. Fifty percent of Mr. Willmott's
     options vested on January 1, 1998, and the remaining 50% were to be vested
     on December 31, 1998. Since Mr. Willmott has left the Company, all of his
     stock options have now been forfeited.
 
(2) Exercise price is the fair market value of the shares of the Company's
     common stock on the date of grant.
 
(3) The Black-Scholes option pricing model has been used to calculate the
     present value of the options as of the date of grant. In calculating grant
     date present values for options granted January 2, 1997 and April 22, 1997
     as set forth in the table, factors of 75% and 73% respectively, have been
     assigned to the volatility of the common stock based on weekly closing
     stock market quotations for the three years preceding the date of grant, no
     dividend yield on the common stock has been assumed, the risk-free rate of
     return has been fixed at 6.54% and 6.84%, respectively, the rate for a ten
     year U.S. Treasury Note on the date of grant and the exercise of the
     options has been assumed to occur at the end of the actual option term of
     ten years. There is no assurance that these assumptions will prove to be
     true in the future. Consequently, the actual value, if any, that an
     executive may realize will depend on the common stock price on the date the
     option is exercised. There is no assurance the value realized by an
     executive will be at or near the value estimated by the Black-Scholes
     model.
 
                                        8
<PAGE>   9
 
     AGGREGATED OPTION/SAR EXERCISES IN 1997 AND YEAR-END OPTION/SAR VALUES
 
     Shown below is information concerning the exercise in 1997 of options to
purchase Company common stock by the Named Executive Officers and the
unexercised options to purchase Company common stock held by the Named Executive
Officers at December 31, 1997. No Named Executive Officers exercised SARs in
1997 and no such Officer currently holds any SARs.
 
<TABLE>
<CAPTION>
                                                              NUMBER OF SECURITIES
                                                             UNDERLYING UNEXERCISED     VALUE OF UNEXERCISED IN-THE-
                           SHARES ACQUIRED                   OPTIONS/SARS AT FISCAL        MONEY OPTIONS/SARS AT
                             ON EXERCISE        VALUE             YEAR-END (#)              FISCAL YEAR-END ($)
          NAME                   (#)         REALIZED ($)   EXERCISABLE/UNEXERCISABLE   EXERCISABLE/UNEXERCISABLE(1)
          ----             ---------------   ------------   -------------------------   ----------------------------
<S>                        <C>               <C>            <C>                         <C>
Peter S. Willmott........           0                0                 60,000/0                     0/0
Michael Ahn..............           0                0                        0                     0/0
Ramesh G. Amin...........           0                0                        0                     0/0
Roger A. Cregg...........           0                0                        0                     0/0
Richard F. Vitkus........           0                0            18,000/30,000                     0/0
Dennis R. Winkleman......      11,667          $61,981                      0/0                     0/0
</TABLE>
 
---------------
 
(1) The exercise price of options held by the Named Executive Officers exceeds
     $5.437 (the closing price of the Company's common stock on December 31,
     1997).
 
ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
                SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS
 
     On November 8, 1995, a change in control of the Company occurred in which
LGE and Semicon acquired a total of 36,569,000 shares of the Company's common
stock ("LGE Change in Control"). The following lists the beneficial ownership of
the Company's common stock, of all persons who are known by the Company, as of
March 31, 1998, to beneficially own more than five percent of the outstanding
shares of the common stock of the Company:
 
<TABLE>
<CAPTION>
                                                              AMOUNT AND NATURE OF      PERCENT
            NAME AND ADDRESS OF BENEFICIAL OWNER              BENEFICIAL OWNERSHIP    OF CLASS(1)
            ------------------------------------              --------------------    -----------
<S>                                                           <C>                     <C>
LG Electronics Inc..........................................       12,059,800(2)         17.9%
20 Yoido-dong
Youngdungpo-gu
Seoul 150-721 Korea
LG Semicon Co., Ltd.........................................       26,095,200            38.6%
891 Taechi-dong
Kangnam-gu
Seoul, Korea
</TABLE>
 
---------------
 
(1) Percentage based on shares issued and outstanding on March 31, 1998.
 
(2) LGE beneficially owns 12,059,800 shares directly as to which it has sole
    voting and dispositive power. Such amount includes 1,586,000 shares
    obtainable through the exercise of stock options. LG Semicon has given LGE
    an irrevocable proxy to vote the 26,095,200 shares owned by LG Semicon as to
    which LG Semicon retains dispositive power.
 
                                        9
<PAGE>   10
 
                        SECURITY OWNERSHIP OF MANAGEMENT
 
     The directors and executive officers of the Company as a group beneficially
own less than 1% of the Company's common stock. No director or nominee for
election as a director or executive officer owns in excess of 1% of the
Company's common stock. The following table lists the number of shares of the
Company's common stock beneficially owned as of March 31, 1998, by each director
of the Company, each of the individuals named in the Summary Compensation Table
and the directors and executive officers of the Company as a group.
 
<TABLE>
<CAPTION>
                               AMOUNT AND NATURE OF                                       AMOUNT AND NATURE OF
                               BENEFICIAL OWNERSHIP                                       BENEFICIAL OWNERSHIP
                           ----------------------------                               ----------------------------
                                     OBTAINABLE THROUGH                                         OBTAINABLE THROUGH
                                        STOCK OPTION                                               STOCK OPTION
NAME OF BENEFICIAL OWNER   OWNED(1)     EXERCISE(2)        NAME OF BENEFICIAL OWNER   OWNED(1)     EXERCISE(2)
-------------------------  --------  ------------------    -------------------------  --------  ------------------
<S>                        <C>       <C>                   <C>                        <C>       <C>
T. Kimball Brooker.......    11,000              12,000    Nam Woo..................         0                   0
Ki-song Cho..............         0                   0    Peter S. Willmott........    25,000              10,000
Eugene B. Connolly.......     2,000               4,000    Michael Ahn..............         0                   0
Robert A. Helman.........     1,000               4,000    Ramesh G. Amin...........         0                   0
Cha Hong (John) Koo......         0                   0    Roger A. Cregg...........         0                   0
S.P Koo..................         0                   0    Dennis R. Winkleman......         0                   0
Hun Jo Lee...............         0                   0    Richard F. Vitkus........    33,000              18,000
Andrew McNally IV........     8,000              12,000    Directors and All
Yong Nam.................         0                   0    Executive Officers
                                                           as a group (16
                                                           persons).................    80,000              60,000
</TABLE>
 
---------------
 
(1) The persons named in the table have sole voting and investment power with
     respect to all shares shown as beneficially owned by them. Includes 30,000
     outstanding shares for Mr. Vitkus which are subject to conditions of
     vesting (one-third vests on the third, fourth and fifth anniversary of the
     May 21, 1996 grant date), forfeiture, restrictions on sales, transfer and
     other dispositions.
 
(2) Includes shares of common stock which, as of March 31, 1998, were subject to
     outstanding stock options exercisable within 60 days.
 
                                       10
<PAGE>   11
 
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized,
 
ZENITH ELECTRONICS CORPORATION
(Registrant)
 
Date:  April 30, 1998
 
By:     /s/ Jeffrey P. Gannon
 
       Jeffrey P. Gannon
       President and
       Chief Executive Officer
 
                                       11
<PAGE>   12
 
                   INDEX TO FINANCIAL STATEMENTS AND EXHIBITS
 
Consolidated Financial Statements
Notes to Consolidated Financial Statements
Report of Independent Public Accountants
Unaudited Quarterly Financial Data
Report of Independent Public Accountants on Financial Statement Schedule
 
Financial Statement Schedule:
     Schedule II -- Valuation and Qualifying Accounts
 
Exhibits:
 
<TABLE>
<S>       <C>
 (3c)     By-Laws of the company, as amended
 (4c)     Second Amendment, effective as of December 31, 1997, to
          Credit Agreement dated as of March 31, 1997, among Zenith
          Electronics Corporation, Citibank N.A., Citicorp North
          America, Inc. and the other lenders named therein
(10j)     Restated and Amended Zenith Salaried Retirement Savings Plan
(10m)     Form of Employee Stock Option Agreement, Long-Term Equity
          Compensation Plan
(10s)     Agreement between Jay Alix & Associates and Zenith
          Electronics Corporation, as amended
(10u)     Letter amendment, dated October 15, 1997, to Receivables
          Purchase Agreement dated as of March 31, 1997, among Zenith
          Electronics Corporation and Zenith Finance Corporation and
          to Zenith Trade Receivable Master Trust Pooling and
          Servicing Agreement dated as of March 31, 1997, among Zenith
          Finance Corporation, Zenith Electronics Corporation and
          Bankers Trust Company
(10ad)    Performance Optimization Plan Agreement, dated April 7,
          1997, with Richard F. Vitkus
(21)      Subsidiaries of the company
(23)      Consent of Independent Public Accountants
(27)      Financial Data Schedule for the Year ended December 31, 1997
</TABLE>
 
                                       22