<PAGE>   1
                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                 QUARTERLY REPORT UNDER SECTION 13 OR 15 (D) OF
                       THE SECURITIES EXCHANGE ACT OF 1934


For quarter ended March 31, 1998
                  --------------

Commission File Number 0-17401
                       -------

                             OPTIMUMCARE CORPORATION
               (Exact name of registrant specified in its charter)

           Delaware                                            33-0218003
-------------------------------                            ---------------------
(State of other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                            Identification No.)

 30011 Ivy Glenn Drive, Ste 219
        Laguna Niguel, CA                                          92677
 ------------------------------                            ---------------------

                                 (714) 495-1100
--------------------------------------------------------------------------------
               (Registrants telephone number, including area code)

                                 Not Applicable
--------------------------------------------------------------------------------
         (Former name, former address and former fiscal year, if changed
                               since last report).

        Indicate by check mark whether the registrant (1) has filed all reports
        required to be filed by Section 13 or 15 (d) of the Securities Exchange
        Act of 1934 during the preceding 12 months (or for such shorter periods
        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 [ ]

        Indicate the number of shares outstanding of each of the issuer's
        classes of common stock, as of the latest practicable date.

<TABLE>
<CAPTION>
                  Class                                   Number of Shares Outstanding
                  -----                                   ----------------------------
<S>                                                                  <C>      
        Common Stock, $.001 par value                                6,902,611
</TABLE>

                                       -1-
<PAGE>   2
                                      INDEX

                             OPTIMUMCARE CORPORATION


PART I         FINANCIAL INFORMATION
------         ---------------------
<TABLE>
<CAPTION>
                                                                   Page
                                                                   ----
<S>            <C>                                                  <C>
Item 1.        Financial Statements (Unaudited)

               Balance Sheets as of March 31, 1998 and               
               December 31, 1997                                     3

               Statements of Income for the Three Months           
               Ended March 31, 1998 and 1997                         4

               Statements of Cash Flows for the Three                
               Months Ended March 31, 1998 and 1997                  5

               Notes to Financial Statements                         6

Item 2.        Management's Discussion and Analysis of               
               Financial Condition and Results of Operations         8


PART II        OTHER INFORMATION                                    10
-------        -----------------                                    


SIGNATURE                                                           11
---------                                                           
</TABLE>

                                       -2-
<PAGE>   3
OPTIMUMCARE CORPORATION
BALANCE SHEETS
(UNAUDITED)
<TABLE>
<CAPTION>
                                                                          MARCH 31       DECEMBER 31
                                                                            1998              1997
                                                                            ----              ----
<S>                                                                     <C>               <C>       
ASSETS                                                                           -                 -
CURRENT ASSETS
  CASH                                                                    $803,300          $945,404
  ACCOUNTS RECEIVABLE, NET OF ALLOWANCE OF $0 AT
     MARCH 31, 1998 AND $560,198 AT DECEMBER 31, 1997                    2,260,271         2,186,906
  PREPAID EXPENSES                                                          70,714            49,246
  PREPAID INCOME TAXES                                                     319,693                 0
                                                                        ----------        ----------
      TOTAL CURRENT ASSETS                                               3,453,978         3,181,556

  NOTES RECEIVABLE FROM OFFICER                                            274,000           274,000

FURNITURE AND EQUIPMENT, LESS ACCUMULATED
  DEPRECIATION OF $100,623 AT MARCH 31, 1998
    AND $90,473 AT DECEMBER 31, 1997                                        77,633            86,685

INTANGIBLE ASSETS, LESS ACCUMULATED AMORTIZATION
  OF $1,479 AT MARCH 31, 1998 AND $1,428 AT
    DECEMBER 31, 1997                                                          596               647

DEFERRED TAX ASSET                                                               0           334,000

OTHER ASSETS                                                                44,283            44,283
                                                                        ----------        ----------
      TOTAL ASSETS                                                      $3,850,490        $3,921,171
                                                                        ==========        ==========
CURRENT LIABILITIES
  ACCOUNTS PAYABLE                                                        $255,080          $270,178
  ACCRUED VACATION                                                          74,818            65,639
  ACCRUED EXPENSES                                                         189,637           111,887
  LINE OF CREDIT                                                                 0           200,000
                                                                        ----------        ----------
      TOTAL CURRENT LIABILITIES                                            519,535           647,704

STOCKHOLDERS' EQUITY
  COMMON STOCK, $.001 PAR VALUE; AUTHORIZED
    20,000,000 SHARES, 6,902,611 SHARES ISSUED
    AND OUTSTANDING AT MARCH 31, 1998 AND DECEMBER 31, 1997                  6,903             6,903
  PAID-IN-CAPITAL                                                        3,356,009         3,356,009
  ACCUMULATED DEFICIT                                                      (31,957)          (89,445)
                                                                        ----------        ----------
      TOTAL STOCKHOLDERS' EQUITY                                        $3,330,955        $3,273,467
                                                                        ----------        ----------
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY                              $3,850,490        $3,921,171
                                                                        ==========        ==========
</TABLE>


See notes to financial statements.

                                      -3-
<PAGE>   4
OPTIMUMCARE CORPORATION                                                        
STATEMENTS OF INCOME                                                           
(UNAUDITED)                                                                    
<TABLE>
<CAPTION>
                                                       THREE MONTHS ENDED      
                                                   MARCH 31           MARCH 31 
                                                     1998               1997   
                                                     ----               ----   
<S>                                               <C>                <C>       
REVENUES                                          $3,192,829         $2,830,580
INTEREST INCOME                                        6,070              1,532
                                                  ----------         ----------
                                                  $3,198,899         $2,832,112
                                                  ----------         ----------
OPERATING EXPENSES:                                                            
COSTS OF SERVICES PROVIDED                        $2,418,898         $2,063,046
PROVISION FOR DOUBTFUL ACCOUNTS                      302,079                  0
GENERAL AND ADMINISTRATIVE                           373,028            411,578
INTEREST                                               2,586             16,627
MINORITY INTEREST                                          0            (10,493
                                                  ----------         ----------
                                                   3,096,591          2,480,758
                                                  ----------         ----------
INCOME BEFORE INCOME TAXES                           102,308            351,354
                                                                               
INCOME TAXES                                          44,820            148,507
                                                  ----------         ----------
NET INCOME                                           $57,488           $202,847
                                                  ==========         ==========
BASIC EARNINGS PER SHARE                               $0.01              $0.03
                                                  ==========         ==========
DILUTED EARNINGS PER SHARE                             $0.01              $0.03
                                                  ==========         ==========
</TABLE>


See notes to financial statements.                                             

                                      -4-
<PAGE>   5
OPTIMUMCARE CORPORATION
STATEMENT OF CASH FLOWS
(UNAUDITED)


<TABLE>
<CAPTION>
                                                                      THREE MONTHS ENDING
                                                                   MARCH 31          MARCH 31
                                                                     1998              1997
                                                                     ----              ----
<S>                                                                <C>                <C>      
CASH FLOW FROM OPERATING ACTIVITIES
  Net Income                                                        $57,488           $202,847
  Adjustments to reconcile net income to net
    cash provided by operating activities:
      Depreciation & Amortization                                    10,201             18,535
      Provision for Doubtful Accounts                               302,079                  0
      Minority Interest                                                   0            (10,493)
      Changes in operating assets and liabilities:
        (Increase) in accounts receivable, net                     (375,444)          (698,872)
        (Increase) in prepaid expenses                              (21,468)            (2,718)
        (Increase) in prepaid income taxes                         (319,693)                 0
        Decrease in deferred tax asset                              334,000                  0
        (Decrease) in accounts payable                              (15,098)            39,604
        Increase in accrued vacation                                  9,179                  0
        Increase in accrued liabilities                              77,750            134,886
                                                                   --------           -------- 
          CASH AND CASH EQUIVALENTS PROVIDED
          (USED) BY OPERATING ACTIVITIES                             58,994           (316,211)

CASH FLOW FROM INVESTING ACTIVITIES
  Purchase of furniture & equipment                                  (1,098)           (30,310)
                                                                   --------           -------- 
          CASH AND CASH EQUIVALENTS (USED)
                  IN INVESTING ACTIVITIES                            (1,098)           (30,310)

CASH FLOW FROM FINANCING ACTIVITIES
  Proceeds from exercise of stock options                                 0              9,375
  Note payable from bank                                           (200,000)                 0
                                                                   --------           -------- 
          CASH AND CASH EQUIVALENTS (USED)/PROVIDED BY
                  FINANCING ACTIVITIES                             (200,000)             9,375

 (DECREASE) IN CASH AND CASH EQUIVALENTS                           (142,104)          (337,146)

Cash and cash equivalents at beginning of period                    945,404          1,113,809
                                                                   --------           -------- 
      CASH AND CASH EQUIVALENTS AT END OF PERIOD                   $803,300           $776,663
                                                                   ========           ========
</TABLE>



See notes to financial statements.

                                      -5-
<PAGE>   6
OPTIMUMCARE CORPORATION
-----------------------

NOTES TO FINANCIAL STATEMENTS (UNAUDITED)

MARCH 31, 1998

NOTE A -- BASIS OF PRESENTATION

The accompanying unaudited financial statements for the three month period ended
March 31, 1998 have been prepared in accordance with generally accepted
accounting principles for interim financial information and with the
instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do
not include all of the information footnotes required by generally accepted
accounting principles for complete financial statements. In the opinion of
management, all adjustments (consisting of normal recurring accruals) considered
necessary for a fair presentation have been included. Operating results for the
three month period ended March 31, 1998 are not necessarily indicative of the
results that may be expected for the year ended December 31, 1998. For further
information, refer to the financial statements and footnotes thereto included in
the Company's Form 10-K for the year ended December 31, 1997.

NOTE B -- ALLOWANCE FOR DOUBTFUL ACCOUNTS

In February, 1997 the Company formed an alliance with Galaxy Health Care, Inc.
to develop community mental health centers. In August, 1997 the company
relicensed its Long Beach, California partial hospitalization program with
Galaxy. In December, 1997, an insurance reimbursement audit of Galaxy's Florida
treatment sites placed Galaxy under severe working capital constraints. The
Company has perfected a security interest in all funds due Galaxy arising from
the operation of the Long Beach program. The allowance for doubtful accounts at
December 31, 1997 reserved all amounts due from Galaxy at that point in time.

During 1998, the Company learned that the magnitude of debt owed by Galaxy from
this audit appeared to be extremely substantial. This has caused the Company to
believe that the collectibility of its receivables covered by the security
interest is remote. As a result, the Company has written off all amounts due
from Galaxy at March 31, 1998.

The Company has terminated its relationship with Galaxy and is seeking a new
host for its partial hospitalization treatment site in Long Beach, California.

The prepaid income tax account at March 31, 1998 and the deferred asset account
at December 31, 1997 represent the tax aspects associated with the accounts
receivable from Galaxy.

NOTE C -- EARNINGS PER SHARE

In 1997, the Financial Accounting Standards Board issued Statement No. 128,
Earnings per Share. Statement 128 replaced the calculation of primary and fully
diluted earnings per share with basic and diluted earnings per share. Unlike
primary earnings per share, basic earnings per share excludes any dilutive
effects of options, warrants and convertible securities. Diluted earnings per
share is very similar to the previously reported fully diluted earnings per
share. All earnings per share amounts for all periods have been presented, and
where appropriate, restated to conform with Statement 128 requirements.

                                       -6-
<PAGE>   7
The following table sets forth the computation of basic and diluted earnings per
share:

<TABLE>
<CAPTION>
                                              MARCH 31, 1998       MARCH 31, 1997
                                              --------------       --------------
<S>                                             <C>                  <C>       
Numerator                                       $   57,488           $  202,847

Denominator:
        Denominator for basic earnings per
         share - weighted-average shares         6,902,611            6,602,051
        Dilutive employee stock options            251,456              500,136
                                                ----------           ----------
        Denominator for diluted earnings per
         share                                   7,154,067            7,302,187
                                                ==========           ==========

        Basic earnings per share                    $.01                $.03

        Diluted earnings per share                  $.01                $.03
</TABLE>


NOTE D -- SUBSEQUENT EVENT

Effective April 9, 1998 the Company consolidated two partial hospitalization
programs located in Baldwin Park, and El Monte, California which were licensed
with one hospital.

A similar consolidation is expected to occur on April 30, 1998 with two partial
hospitalization programs located in Glendale, and Sherman Oaks, California which
were licensed with one hospital.


                                       -7-
<PAGE>   8
MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF
OPERATION

SAFE HARBOR STATEMENTS UNDER THE PRIVATE SECURITIES LITIGATION REFORM ACT OF
----------------------------------------------------------------------------
1995
----

Management's Discussion and Analysis of Financial Condition and Results of
Operations contains statements which are forward-looking in time and involve
risks and uncertainties, including the risks associated with plans, the effects
of changing economic and competitive conditions, government regulation which may
affect facilities, licensing, healthcare reform which may affect payment amounts
and timing, availability of sufficient working capital, Program development
efforts and timing and market acceptance of new Programs which may affect future
sales growth and/or costs of operations.

MATERIAL CHANGES IN FINANCIAL CONDITION
---------------------------------------

At March 31, 1998 and December 31, 1997, the Company's working capital was
$2,934,443 and $2,533,852 respectively. The nature of the Company's business
requires significant working capital to fund operations of its programs as well
as to fund corporate expenditures until receivables can be collected. Moreover,
because each of the existing contracts represents a significant portion of the
Company's business, the inability to collect any of the accounts receivable
could materially and adversely affect the Company's liquidity. Despite the
write-off of the Galaxy receivable previously discussed in Note B of the Notes
to the Financial Statements, the Company has been able to effectively manage
collections on other receivables and payments for services in a manner which has
not impaired its working capital.

Cash flows from operations were $58,994 and ($316,221) for the periods ended
March 31, 1998 and 1997, respectively. Positive cash flow for the three months
ended March 31, 1998 is primarily due to the net income for the period.

Cash flows used in investing activities were ($1,098) and ($30,310) for the
periods ended March 31, 1998 and 1997, respectively. Funds used during both
periods were expended for office furniture and equipment.

The cash flows used in financing activities were ($200,000) for the period ended
March 31, 1998. Funds used during 1998 were pay downs on the Company's line of
credit agreement with a bank, which were drawn during 1997. The line of credit
expired May 1, 1998. The maximum indebtedness is $1,500,000. Amounts allowable
for draw are based on 75% of certain qualified accounts receivable. As of April
29, 1998, approximately $1,450,000 is available for future draws on the line of
credit agreement. It is expected that the line of credit will be renewed on
similar terms. The Company's principal sources of liquidity for the fiscal year
1998 are cash on hand, accounts receivable, the line of credit with a bank and
continuing revenues from programs. Funds provided of $9,375 during the period
ended March 31, 1997 were obtained from the exercise of one employee stock
option.

                                       -8-
<PAGE>   9
MATERIAL CHANGES IN RESULTS OF OPERATIONS
-----------------------------------------

Three Months Ended March 31, 1998 compared to Three Months Ended March 31, 1997
-------------------------------------------------------------------------------

The Company operated twelve (12) programs during the three months ended March
31, 1998 and thirteen (13) programs during the three months ended March 31,
1996. Net Revenues were $3,192,829 and $2,830,580 for the three months ended
March 31, 1998 and 1997, respectively. The increase in revenues for the three
months ended March 31, 1998 over March 31, 1997 is due to the census increase at
one partial hospitalization program and an increase in the Company's management
fee and contract responsibilities for one other partial hospitalization program
which the Company relicensed with a community mental health center in August,
1997.

Cost of services provided were $2,418,898 and $2,063,046 for the three months
ended March 31, 1998 and 1997 respectively. The increase in the cost of services
provided among periods is primarily due to the increase in certain treatment
costs at one partial hospitalization program. The Company became responsible for
assuming all direct costs of the program following a relicensure of the program
with a community mental health center in August, 1997. Other smaller increases
in the cost of services provided occurred due to the increase in treating
patient volume among periods and the increase in dietary costs for two programs
which the Company began to assume responsibility for during the last half of
1997.

The provision for doubtful accounts at March 31, 1998 represents the write-off
of the receivables generated from the Galaxy alliance during the three months
ending March 31, 1998 as previously discussed in Note B to the Financial
Statements. Management believes the collectibility of these receivables is
remote. No such similar situation existed during the three month period ending
March 31, 1997.

Selling, general and administrative expenses for the three months ending March
31, 1998 have decreased over the three months ending March 31, 1997 primarily
due to decreased executive wages based on profit orientated incentive bonus
programs.

Net income was $57,488 and $202,847 for the three months ending March 31, 1998
and 1997, respectively. The decrease was primarily attributable to write-off of
the Galaxy receivables discussed above.

The Company anticipates the costs of operating its programs to decrease as a
result of the consolidation of certain of its partial hospitalization program
discussed in Note D of the financial statements. While revenues are also
expected to decrease as a result of the consolidation, the Company expects to
achieve economics of scale by operating these programs at maximum capacity. The
Company has continued to provide a larger scope of services to its customers for
a greater management fee. Census increase due to the maturity of existing
programs and changes in fee services of programs should cause revenues to
increase, and gross profit to rise favorably and disproportionately due to the
increase in costs for such programs. However, should patient census and the
resulting revenue decrease (especially below the minimum break even level) costs
could be disproportionately high which would adversely impact the results of
operations and the Company's available resources. Due to the Company's
dependence on a relatively small customer base presently consisting only four
(4) hospitals and one community mental health center, the loss of any of its
customers could have a significant adverse effect on the Company's operations.


                                       -9-
<PAGE>   10
                                     PART II

                                OTHER INFORMATION
                                -----------------


ITEM 1                LEGAL PROCEEDINGS
------                -----------------

                      Not applicable.


ITEM 2                CHANGES IN SECURITIES
------                ---------------------

                      Not applicable.


ITEM 3                DEFAULTS UPON SENIOR SECURITIES
------                -------------------------------

                      Not applicable.


ITEM 4                SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
------                ---------------------------------------------------

                      Not applicable.


ITEM 5                OTHER INFORMATION
------                -----------------

                      Not applicable.


ITEM 6                EXHIBITS AND REPORTS ON FORM 8-K
------                --------------------------------

                      On January 29, 1998 the Company filed a report on Form 8-K
                      announcing the postponement of the opening of treatment
                      sites with Galaxy Health Care, Inc.

                      On March 19, 1998 the Company filed a report on Form 8-K
                      announcing the termination of the Galaxy Health Care
                      alliance and a charge to earnings relating to the
                      write-off of funds owed to the Company by Galaxy. The
                      report also announced the write-off of acquisition costs
                      related to the 1996 acquisition of OptimumCare Source, LLC
                      and the approval of a stock repurchase program whereby the
                      Company may purchase up to 500,000 shares of its own
                      common stock over the next twelve months.


                                      -10-
<PAGE>   11
                                    SIGNATURE


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 authorized.


                                                   OPTIMUMCARE CORPORATION
                                                   A Delaware Corporation



Dated:  May 5, 1998                                By:    EDWARD A. JOHNSON
                                                          -----------------
                                                          Edward A. Johnson
                                                          President & Principal
                                                          Financial Officer



                                      -11-