<PAGE>   1


                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-Q

[X]     Quarterly report pursuant to Section 13 or 15(d) of the Securities
        Exchange Act of 1934 
        For the quarterly period ended March 31, 1998, or

[ ]     Transition report pursuant to Section 13 or 15(d) of the Securities 
        Exchange Act of 1934
        For the transition period from      to       .

                           Commission File No. 0-13787


                              INTERMET CORPORATION
             (Exact name of registrant as specified in its charter)


                  GEORGIA                        58-1563873
       (State or other jurisdiction of         (IRS Employer
       incorporation or organization)          Identification No.)


           5445 Corporate Drive, Suite 200, Troy, Michigan 48098-2683
            (Address of principal executive offices)       (Zip code)


                                 (248) 952-2500
              (Registrant's telephone number, including area code)


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 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

At April 24, 1998 there were 25,590,624 shares of Common Stock, $0.10 par value,
outstanding.




<PAGE>   2


                         PART I - FINANCIAL INFORMATION

ITEM 1.    FINANCIAL STATEMENTS

                              Intermet Corporation

                  Interim Condensed Consolidated Balance Sheets
<TABLE>
<CAPTION>

                                                                    March 31,         December 31,
                                                                      1998                1997
                                                                  ----------------    ------------
                                                                  (Unaudited)
                                                                      (in thousands of dollars)
<S>                                                                  <C>              <C>     
Assets
Current assets:
 Cash and cash equivalents                                           $  6,066         $  7,022
 Accounts receivable:
  Trade, less allowance for doubtful accounts of $1,736
  in 1998 and $2,125 in 1997                                          106,901           92,871
  Other                                                                12,000            7,549
                                                                     --------         --------
                                                                      118,901          100,420

   Inventories                                                         58,387           61,164
   Other current assets                                                27,662           24,676
                                                                     --------         --------

Total current assets                                                  211,016          193,282

Property, plant and equipment, at cost                                455,779          471,981
Less:
 Foreign industrial development grants, net of
  amortization                                                          5,316            5,638
 Accumulated depreciation and amortization                            223,171          224,444
                                                                     --------         --------
Net property, plant and equipment                                     227,292          241,899

Goodwill, net of amortization                                          89,601           86,014
Other noncurrent assets                                                21,405           17,610
                                                                     --------         --------

                                                                     $549,314         $538,805
                                                                     ========         ========
</TABLE>



                                       2
<PAGE>   3


                              Intermet Corporation

                  Interim Condensed Consolidated Balance Sheets
<TABLE>
<CAPTION>

                                                                    March 31,          December 31, 
                                                                      1998                 1997
                                                               -------------------    ---------------
                                                                  (Unaudited)
                                                                      (in thousands of dollars)

<S>                                                               <C>                  <C>   
Liabilities and shareholders' equity 
Current liabilities:
 Notes payable                                                    $   3,319            $   9,087
 Accounts payable                                                    56,226               59,173
 Income taxes payable                                                15,137                8,635
 Accrued liabilities                                                 52,846               48,521
 Long term debt due within one year                                   9,632               10,538
                                                                  ---------            ---------
Total current liabilities                                           137,160              135,954

Noncurrent liabilities:
 Long term debt due after one year                                  165,143              167,295
 Retirement benefits                                                 50,319               49,013
 Other noncurrent liabilities                                         6,286                8,778
                                                                  ---------            ---------
Total noncurrent liabilities                                        221,748              225,086

Minority interest                                                     1,688                2,337

Shareholders' equity:
 Common stock                                                         2,560                2,526
 Capital in excess of par value                                      61,248               58,176
 Retained earnings                                                  124,493              114,242
 Accumulated other comprehensive income                                 484                  561
 Unearned restricted stock                                              (67)                 (77)
                                                                  ---------            ---------
Total shareholders' equity                                          188,718              175,428
                                                                  ---------            ---------

                                                                  $ 549,314            $ 538,805
                                                                  =========            =========
</TABLE>
See accompanying notes.

                                       3

<PAGE>   4


                              Intermet Corporation

               Interim Condensed Consolidated Statements of Income



<TABLE>
<CAPTION>

                                                          Three months ended
                                                      March 31,        March 31,
                                                        1998              1997
                                                     -------------    ----------
                                                              (Unaudited)
                                                      (in thousands of dollars, 
                                                        except per share data)


<S>                                                   <C>             <C>      
Net sales                                             $ 224,033       $ 209,491
Cost of sales                                           194,058         181,886
                                                      ---------       ---------
Gross profit                                             29,975          27,605

Operating expenses:
 Selling                                                  2,604           2,027
 General and administrative                               5,197           5,459
                                                      ---------       ---------
                                                          7,801           7,486

                                                      ---------       ---------
Operating profit                                         22,174          20,119

Other income and expenses:
 Interest income                                             50             233
 Interest expense                                        (3,422)         (2,997)
 Other, net                                                 768             353
                                                      ---------       ---------

                                                         (2,604)         (2,411)
                                                      ---------       ---------

Income before income taxes and minority
interest                                                 19,570          17,708
Provision for income taxes                                8,606           6,757
                                                      ---------       ---------

Income before minority interest                          10,964          10,951
Minority interest in loss of subsidiary                     307            --

                                                      =========       =========
Net income                                            $  11,271       $  10,951
                                                      =========       =========

Income per common share - Basic                       $    0.44       $    0.43
                                                      =========       =========

Income per common share - Diluted                     $    0.43       $    0.43
                                                      =========       =========
</TABLE>
See accompanying notes.


                                       4
<PAGE>   5


                              Intermet Corporation

             Interim Condensed Consolidated Statements of Cash Flows
<TABLE>                                                              
<CAPTION>    
    
                                                                             Three months ended
                                                                      March 31, 1998    March 31, 1997
                                                                     ----------------  ----------------
                                                                                (Unaudited)
                                                                         (in thousands of dollars)
<S>                                                                  <C>               <C>     
Operating activities:    
Net income                                                                 $ 11,271        $ 10,951      
Adjustments to reconcile net income to cash provided by operating                                        
 activities:                                                                                             
 Depreciation and amortization                                                9,959           9,290      
 Other, including net gain on disposal of fixed assets                         (574)           (644)     
 Changes in operating assets and liabilities excluding the effects of                                
 acquisitions and dispositions:                                                                          
 Accounts receivable                                                        (19,096)        (25,927)     
 Inventories                                                                  2,544             205      
 Accounts payable and accrued liabilities                                     3,766           2,889      
 Other assets and liabilities                                                 2,882           5,972      
                                                                           --------        --------      
Net cash provided by operating activities                                    10,752           2,736      
                                                                                                         
Investing activities:                                                                                    
 Additions to property, plant and equipment                                  (7,565)         (7,871)     
 Sudbury acquisition                                                            (95)        (34,027)     
 Proceeds from disposal of fixed assets                                       1,395             901      
 Other                                                                         (612)           --        
                                                                           --------        --------      
Net cash used in investing activities                                        (6,877)        (40,997)     
                                                                                                         
Financing activities:                                                                                    
 Net (decrease) increase in revolving credit facility                        (1,000)         40,600      
 Reduction in debt                                                           (1,188)        (10,594)     
 Net decrease in notes payable                                               (5,657)           --        
 Issuance of common stock                                                     3,106             332      
 Dividends paid                                                              (1,020)         (1,009)     
 Other                                                                          --            1,564      
                                                                           --------        --------      
Net cash (used in) provided by financing activities                          (5,759)         30,893      
                                                                                                         
Effect of exchange rate changes on cash and cash equivalents                    928          (1,984)     
                                                                           --------        --------      
                                                                                                         
Net decrease in cash and cash equivalents                                      (956)         (9,352)     
                                                                                                         
Cash and cash equivalents at beginning of period                              7,022          23,485      
                                                                           --------        --------      
                                                                                                         
Cash and cash equivalents at end of period                                 $  6,066        $ 14,133      
                                                                           ========        ========      
</TABLE>    
    
See accompanying notes.    
    
    
    
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<PAGE>   6


                              Intermet Corporation

          Notes to Interim Condensed Consolidated Financial Statements

                           March 31, 1998 (Unaudited)


1.   Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements of
Intermet Corporation ("Intermet") and its subsidiaries (collectively, the
"Company") 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 and 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 months
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 consolidated financial statements and footnotes thereto included in the
Company's annual report on Form 10-K for the year ended December 31, 1997.

Inventories

Inventories consist of the following (in thousands of dollars):
<TABLE>
<CAPTION>

                                                      March 31,     December 31,
                                                        1998            1997
                                                    -------------   ------------
<S>                                                    <C>             <C>     
Finished goods                                         $12,003         $13,852 
Work in process                                         15,686          13,897 
Raw materials                                           10,672          11,533 
Supplies and patterns                                   20,026          21,882 
                                                       -------         ------- 
                                                       $58,387         $61,164 
                                                       =======         ======= 
</TABLE>


Property, Plant and Equipment

Property, plant and equipment consist of the following (in thousands of
dollars):

<TABLE>
<CAPTION>

                                                 March 31,      December 31,
                                                   1998             1997
                                                 ---------      ------------
<S>                                              <C>              <C>     
Land                                             $  4,199         $  4,783
Buildings and improvements                         84,583           89,215
Machinery and equipment                           353,660          357,745
Construction in progress                           13,337           20,238
                                                 --------         --------
                                                 $455,779         $471,981
                                                 ========         ========
</TABLE>





                                       6
<PAGE>   7


                              Intermet Corporation

    Notes to Interim Condensed Consolidated Financial Statements (continued)

                           March 31, 1998 (Unaudited)


1.       Summary of Significant Accounting Policies (continued)

Intangible Assets

Intangible assets consist principally of costs in excess of net assets acquired
of $89,601,000 and $86,014,000 (net of accumulated amortization of $5,056,000
and $4,392,000) at March 31, 1998 and December 31, 1997, respectively. Such
costs are being amortized using the straight-line method over periods ranging
from ten to forty years.

Income per Common Share

Net income per common share amounts were previously based on the weighted
average number of shares outstanding during the period, after giving effect to
the exercise of options and assuming the repurchase, at fair market value, of
shares using the proceeds from such exercise, unless the effect was
antidilutive. In February 1997, the Financial Accounting Standards Board
("FASB") issued Statement No. 128, "Earnings per Share", which was adopted by
the Company on December 31, 1997. Under the new requirements for calculating
basic earnings per share, the dilutive effect of stock options are excluded.
Fully diluted EPS has not changed significantly but has been renamed diluted
EPS. Earnings per share for all prior periods have been restated to reflect the
new accounting standard.

Reclassification

Certain amounts previously reported in the 1997 financial statements and notes
thereto have been reclassified to conform to the 1998 presentation.

2.   Debt

Long term debt consists of the following (in thousands of dollars):

<TABLE>
<CAPTION>

                                                March 31,     December 31,
                                                  1998            1997
                                                ---------     ------------

<S>                                             <C>             <C>
Intermet                                        $144,000        $150,000
Subsidiaries                                      30,775          27,833
                                                --------        --------

Total long-term debt                             174,775         177,833
Less amounts due within one year                   9,632          10,538
                                                --------        --------

Long-term debt due after one year               $165,143        $167,295
                                                ========        ========
</TABLE>



                                       7
<PAGE>   8




                             INTERMET CORPORATION

   Notes to Interim Condensed Consolidated Financial Statements (continued)

                          March 31, 1998 (Unaudited)



3.  Comprehensive Income

During 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 130, "Reporting Comprehensive Income", which
the Company adopted as of January 1, 1998.  Statement 130 establishes new rules
for reporting and display of comprehensive income and its components.  However,
the adoption of this Statement had no impact on the Company's net income or
shareholders' equity.  Statement 130 requires these items, which include foreign
currency translation adjustment and minimum pension liability adjustment, to be
combined and reported as accumulated other comprehensive income.  Prior to
adoption, these items were reported separately in shareholders' equity.  In
addition, the Statement requires net income and other comprehensive income to
be included as components of total comprehensive income, as displayed in the
table below.


<TABLE>
<CAPTION>
                                                        Three months ended
                                                        ------------------
                                                     March 31,        March 31,
                                                       1998             1997
                                                     ---------        ---------
                                                      (in thousands of dollars)
<S>                                                 <C>               <C>
        Net income                                   $11,271           $10,951
        Other comprehensive loss:
         Foreign currency translation adjustment         (77)           (1,668)
         Minimum pension liability adjustment              -                 -
                                                     -------           -------
        Total other comprehensive loss                   (77)           (1,668)
                                                     -------           -------
        Total comprehensive income                   $11,194           $ 9,283
                                                     =======           =======

</TABLE>

Prior year financial statements have been reclassified to conform to the
requirements of Statement 130.

4.  Environmental and Legal Matters.

The Company is engaged in various legal proceedings and other matters
incidental to its normal business activities.  The Company does not believe
any of the above mentioned proceedings or matters are material in relation to
the Company's consolidated financial position or results of operations.



                                      8
<PAGE>   9


                              Intermet Corporation

    Notes to Interim Condensed Consolidated Financial Statements (continued)

                           March 31, 1998 (Unaudited)


5.   Earnings per Share

Basic earnings per share is computed by dividing income available to common
shareholders by the weighted average number of common shares outstanding for the
period. The dilutive earnings per share calculation reflects the assumed
exercise of stock options.


<TABLE>
<CAPTION>

                                                            Three months ended
                                                       ------------------------------
                                                        March 31,        March 31,
                                                           1998             1997
                                                       -------------    -------------
                                                         (in thousands, except per
                                                                share data)

<S>                                                    <C>              <C>    
       Numerator:
         Net income                                    $      11,271    $      10,951

       Denominator:
         Denominator for basic earnings per
            share - weighted average shares                   25,404           25,178

         Effect of dilutive securities:
            Employee stock options                               548              501
                                                       -------------    -------------
         Denominator for diluted earnings per
            share - adjusted weighted average
            shares and assumed conversions                    25,952           25,679
                                                       =============    =============

       Basic earnings per share                                $0.44            $0.43
                                                       =============    =============

       Diluted earnings per share                              $0.43            $0.43
                                                       =============    =============
</TABLE>



                                       9
<PAGE>   10


ITEM 2.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND 
           RESULTS OF OPERATIONS

Material Changes in Financial Condition

For the first three months of 1998, net cash provided by operating activities
was $10.8 million. Accounts receivable increased $19.1 million from December 31,
1997, as sales during March 1998 were higher than those of December 1997,
excluding IWESA, due to the traditional holiday shutdown. Depreciation and
amortization expense was $10.0 million. The Company's investing activities for
the first three months of 1998 used cash of $6.9 million. This includes
additions to property, plant and equipment of $7.6 million. In addition, the
Company received $1.4 million of proceeds on the sale of fixed assets. Financing
activities used cash of $5.8 million for the year to date at March 31, 1998. A
portion of the cash generated from operations was used to reduce bank borrowings
$7.8 million from the end of 1997. The Company received $3.1 million from the
exercise of stock options.

Cash and cash equivalents decreased to $6.1 million at March 31, 1998 from $7.0
million at December 31, 1997. The Company declared a cash dividend of $0.04 per
share ($1.0 million in aggregate) for the holders of record on March 2, 1998.

Material Changes in Results of Operations

SALES. Sales in the first quarter of 1998 were $224.0 million compared to $209.5
million during the same period in 1997. Domestic foundry sales during the three
months ended March 31, 1998 were approximately $6.5 million (or 4.9%) higher
than sales for the same period in 1997. This is a result of an increase in
domestic vehicle sales, primarily light trucks and sport utility vehicles,
including; Ford PHN131, Mercedes SUV and Dodge Durango programs. Sales at
machining operations increased $7.4 million for the first quarter of 1998 over
the same period in 1997. This is due primarily to the inclusion of IWESA, which
was accounted for under the equity method in 1997 but is consolidated for the
first quarter of 1998. European foundry sales were up 22.4% for the first
quarter for 1998 versus the same period for 1997 as a result of an improved
vehicle market. However, the negative effect of changes in the exchange rates on
sales was $2.5 million (or 9.1%) for first quarter of 1998 compared to exchange
rates for the same period in 1997.

GROSS PROFIT. Gross profit for the quarter ended March 31, 1998 was $30.0
million, an increase of $2.4 million from that of the same period in 1997. Gross
profit as a percentage of sales for the three months ended March 31, 1998 and
1997 were 13.4% and 13.2%, respectively. Without the highly leveraged IWESA
operations, gross profit as a percentage of sales would be almost 0.9% higher.

SELLING, GENERAL AND ADMINISTRATIVE EXPENSES. Selling, general and
administrative expenses as a percentage of sales were 3.5% and 3.6% for the
three months ended March 31, 1998 and 1997, respectively.

INTEREST EXPENSE. Interest expense increased to $3.4 million from $3.0 million
for the period ended March 31, 1998 versus that period in 1997.



                                       10
<PAGE>   11


                           PART II - OTHER INFORMATION

ITEM 1.    LEGAL PROCEEDINGS

The Company is not aware of any material pending or threatened legal proceedings
to which the Company is a party or of which any of its property is the subject.

ITEM 2.    CHANGES IN SECURITIES AND USE OF PROCEEDS

None

ITEM 3.    DEFAULTS UPON SENIOR SECURITIES

None

ITEM 4.    SUBMISSION OF MATTERS TO A VOTE OF SECURITIES HOLDERS

None

ITEM 5.    OTHER INFORMATION

In February 1997, the Company announced an agreement in principle to purchase a
50% ownership interest in POLCAST Sp. z o.o. In April 1998, the Company
terminated all negotiations relating to this purchase. 

ITEM 6.    EXHIBITS AND REPORTS ON FORM 8-K

(a) The following exhibits are filed with this Report pursuant to Item 601 of
Regulation S-K:


Exhibit Number   Description of Exhibit

27.1             Financial Data Schedule.


(b) The Company filed no reports on Form 8-K during the three months ended March
31, 1998.


                                       11
<PAGE>   12


                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Company
has duly caused this report to be signed on its behalf by the undersigned
thereunto duly authorized.


                                     INTERMET CORPORATION


                                     By:      /s/ Walter T. Knollenberg
                                              ----------------------------------
                                              Walter T. Knollenberg
                                              Corporate Controller
                                              (Principal Accounting Officer)

                                     Date:    April 24, 1998












                                       12
<PAGE>   13


Exhibits Index


Exhibit Number        Description of Exhibit

27.1                  Financial Data Schedule.





















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