<PAGE>   1
                      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 QUARTER ENDED JUNE 30, 1997

                                      or

              TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934

                               Commission File
                                  No. 1-5210

                            AMERISTEEL CORPORATION

                               Incorporated in
                               STATE OF FLORIDA

                           Employer Identification
                                NO. 59-0792436

                             5100 W. LEMON STREET
                             TAMPA, FLORIDA 33609

                               Mailing Address:
                               P. O. Box 31328
                          Tampa, Florida 33631-3328
                         Telephone No. (813)286-8383

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, and (2) has been subject to such filing
requirements for the past 90 days.

                                  Yes   X   No
                                      -----   -----

      As of July 31, 1997 the registrant had 10,074,885 shares $.01 par
                       value common stock outstanding.

<PAGE>   2


                       PART I -- FINANCIAL INFORMATION

ITEM I.  FINANCIAL STATEMENTS

AMERISTEEL CORPORATION
STATEMENTS OF FINANCIAL POSITION
($ in thousands)

<TABLE>
<CAPTION>

                                                          JUNE 30,       MARCH 31,
                                                            1997           1997
                                                        (UNAUDITED)      
                                                        ------------    ---------
<S>                                                      <C>            <C>     
ASSETS

CURRENT ASSETS
      Cash and cash equivalents                          $  3,306       $  1,645
      Accounts receivable                                  77,973         68,563
      Inventories                                         104,905        106,173
      Deferred tax assets                                   5,000          5,000
      Other current assets                                  1,122          1,138
                                                         --------       --------
               TOTAL CURRENT ASSETS                       192,306        182,519
                                                         
ASSETS HELD FOR SALE                                       14,967         14,838
                                                         
PROPERTY, PLANT AND EQUIPMENT                             310,507        308,159
      Less accumulated depreciation                        62,924         58,138
                                                         --------       --------
                                                          247,583        250,021

GOODWILL                                                   84,740         85,773
                                                         
DEFERRED FINANCING COSTS                                    2,289          2,523
                                                         
OTHER ASSETS                                                    7             11
                                                         --------       --------
                                                         
TOTAL ASSETS                                             $541,892       $535,685
                                                         ========       ========
</TABLE>


      See notes to financial statements




                                      2
<PAGE>   3


AMERISTEEL CORPORATION
STATEMENTS OF FINANCIAL POSITION -- continued
($ in thousands)

<TABLE>
<CAPTION>

                                                                                     JUNE 30,    MARCH 31,
                                                                                       1997         1997
                                                                                   (UNAUDITED)
                                                                                   ----------   ----------
<S>                                                                                <C>          <C>
LIABILITIES AND SHAREHOLDERS' EQUITY

CURRENT LIABILITIES
      Trade accounts payable                                                       $  40,482    $  44,666
      Salaries, wages and employee benefits                                           14,470       14,598
      Environmental remediation                                                        5,633        5,079
      Other current liabilities                                                        9,615        4,355
      Interest payable                                                                 1,745        4,659
      Current maturities of long-term borrowings                                       5,687          435
                                                                                   ---------    ---------
                          TOTAL CURRENT LIABILITIES                                   77,632       73,792                        
                                                                                     
LONG -TERM BORROWINGS, LESS CURRENT PORTION                                          231,745      237,474
                                                                                     
OTHER LIABILITIES                                                                     21,045       21,555

DEFERRED TAX LIABILITIES                                                              52,300       52,300

SHAREHOLDERS' EQUITY
      Common stock, $.01 par value; 30,000,000 shares authorized at June 30, and
        March 31, 1997, 10,075,174 and 10,079,028 shares outstanding at June 30,
        and March 31, 1997, respectively                                                 101          101
      Capital in excess of par                                                       156,765      156,816
      Retained earnings (accumulated deficit)                                          4,095       (4,328)
      Deferred compensation                                                           (1,791)      (2,025)
                                                                                   ---------    ---------
                          TOTAL SHAREHOLDERS' EQUITY                                 159,170      150,564
                                                                                   ---------    ---------
                                                                                  
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY                                         $ 541,892    $ 535,685
                                                                                   =========    =========
</TABLE>



      See notes to financial statements





                                      3
<PAGE>   4


AMERISTEEL CORPORATION
STATEMENTS OF INCOME
($ in thousands except per common share)

<TABLE>
<CAPTION>
                                                  THREE MONTHS ENDED
                                                 JUNE 30,     JUNE 30,
                                                   1997         1996
                                               (UNAUDITED)   (UNAUDITED)
                                                --------      --------
<S>                                             <C>           <C>         
NET SALES                                       $168,359      $169,822    
                                                                          
Operating Expenses:                                                       
     Cost of sales, excluding depreciation       135,037       148,912    
     Selling and administrative                    7,572         6,933    
     Depreciation                                  4,827         3,995    
     Amortization of goodwill                      1,033         1,033    
                                                --------      --------    
                                                 148,469       160,873    
                                                --------      --------    
INCOME FROM OPERATIONS                            19,890         8,949    
                                              
Other Expenses:                                                           
     Interest                                      5,188         4,855    
     Amortization of deferred financing costs        234           234    
                                                --------      --------    
                                                   5,422         5,089    
                                                --------      --------    
INCOME BEFORE INCOME TAXES                        14,468         3,860    
                                                                          
Income taxes                                       6,045         1,908    
                                                --------      --------    
                                                                          
NET INCOME                                      $  8,423      $  1,952    
                                                ========      ========    
                                                                          
Weighted average common shares outstanding                                
     (in thousands)                               10,098        10,094    
                                              
EARNINGS PER COMMON SHARE                       $   0.83      $   0.19    
                                                ========      ========    
</TABLE>



See notes to financial statements




                                      4
<PAGE>   5


AMERISTEEL CORPORATION
STATEMENTS OF CASH FLOWS
($ in thousands)

<TABLE>
<CAPTION>

                                                                 THREE MONTHS ENDED
                                                                 JUNE 30,    JUNE 30,
                                                                   1997       1996
                                                               (UNAUDITED) (UNAUDITED)
                                                                --------    --------
<S>                                                             <C>         <C>     
OPERATING ACTIVITIES
Net income                                                      $  8,423    $  1,952
Adjustments to reconcile net income to net cash
 provided by operating activities:
    Depreciation and amortization                                  6,094       5,262
    Deferred income taxes                                             --         500
    Other (loss on asset disposals and deferred compensation)        740         295
                                                                   

Changes in operating assets and liabilities:
    Accounts receivable                                           (9,410)     (4,156)
    Inventories                                                    1,268      14,942
    Other assets                                                    (109)        268
    Accounts payable, income taxes and other liabilities          (1,923)       (666)
                                                                --------    --------

NET CASH PROVIDED BY OPERATING ACTIVITIES                          5,083      18,397

INVESTING ACTIVITIES
    Additions to property, plant and equipment                    (2,895)    (13,514)
    Proceeds from sales of property, plant and equipment               1         127
    Use of restricted IRB funds                                       --       4,017
                                                                --------    --------
NET CASH USED IN INVESTING ACTIVITIES                             (2,894)     (9,370)

FINANCING ACTIVITIES
    Payments to short-term and long-term borrowings, net            (477)     (9,375)
    Redemption of common stock                                       (51)        (44)
                                                                --------    --------

NET CASH USED IN FINANCING ACTIVITIES                               (528)     (9,419)
                                                                --------    --------

INCREASE (DECREASE) IN CASH
    AND CASH EQUIVALENTS                                           1,661        (392)

CASH AND CASH EQUIVALENTS AT
    BEGINNING OF PERIOD                                            1,645       6,193
                                                                --------    --------

CASH AND CASH EQUIVALENTS AT
    END OF PERIOD                                               $  3,306    $  5,801
                                                                ========    ========
</TABLE>



See note to financial statements



                                      5
<PAGE>   6


AMERISTEEL CORPORATION
NOTES TO FINANCIAL STATEMENTS

NOTE A -- BASIS OF PRESENTATION

The financial statements include the accounts of AmeriSteel, a Florida
corporation, (the "Company"). As of April 1, 1996, the Company changed its name
from Florida Steel Corporation (which it had used since 1956) to AmeriSteel
Corporation. The predecessor of the Company was formed in 1937. All significant
intercompany accounts and transactions have been eliminated.

The accompanying unaudited condensed financial statements have been prepared in
accordance with the instructions for Form 10-Q and, therefore, do not include
all the information or footnotes necessary for a complete presentation of
financial condition, results of operations and cash flows in conformity with
generally accepted accounting principles. However all adjustments which, in the
opinion of management are necessary for a fair presentation, have been included.
Such adjustments consisted of only normally recurring items.

It is suggested that these condensed financial statements be read in conjunction
with the financial statements and the notes thereto included in the Company's
latest annual report on Form 10-K. The results of the three months ended June
30, 1997 are not necessarily indicative of the results to be expected for the
fiscal year ending March 31, 1998.

NOTE B - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Recent Accounting Pronouncements: In February 1997, the Financial Accounting
Standards Board issued Statement No. 128, "Earnings per Share" which establishes
standards for computing and presenting earnings per share. The statement
replaces the presentation of primary earnings per share with a presentation of
basic earnings per share. It also requires dual presentation of basic and
diluted earnings per share on the income statement and provides for certain
disclosures. The Company will adopt Statement No. 128 in the third quarter of
fiscal 1998 and does not believe the effect of adoption will be material.

In June 1997, the Financial Accounting Standards Board issued Statement No. 131,
"Disclosures about Segments of an Enterprise and Related Information" which
establishes standards for reporting information about operating segments of a
business. The statement, which is based on the management approach to segment
reporting, includes requirements to report selected segment information and
entity-wide disclosures about products and services, major customers, and the
countries in which the Company holds assets and reports revenues. This statement
becomes effective for the Company for reporting beginning in fiscal 1999.
Management has not yet evaluated the effects of this change on the Company's
financial statements.

Reclassifications: Certain amounts in the prior period financial statements have
been reclassified to conform to the current fiscal financial statement
presentation.




                                      6
<PAGE>   7

AMERISTEEL CORPORATION
NOTES TO FINANCIAL STATEMENTS

NOTE C -- INVENTORIES

Inventories consist of the following:
     ($ in thousands)

<TABLE>
<CAPTION>
                                                                         JUNE 30,                MARCH 31,       
                                                                           1997                    1997          
                                                                       (UNAUDITED)                               
                                                                       ----------                --------        
<S>                                                                      <C>                     <C>             
Finished goods                                                           $ 61,230                $ 59,299        
                                                                                                                 
Work in-process                                                            12,753                  14,175        
                                                                                                                 
Raw materials and operating supplies                                       30,922                  32,699        
                                                                         --------                --------                         
                                                                         $104,905                $106,173
                                                                         ========                ========        
</TABLE>


NOTE D -- BORROWINGS


Long-term borrowings consist of the following:
    ($ in thousands)

<TABLE>
<CAPTION>

                                                                          JUNE 30,               MARCH 31,
                                                                            1997                    1997
                                                                         ---------               --------
      <S>                                                                 <C>                    <C>
      Revolving Credit Agreement                                          $ 50,870               $ 51,340
      First Mortgage Notes                                                 100,000                100,000
      Subordinated Intercompany Note                                        50,000                 50,000
      Industrial Revenue Bonds                                              30,875                 30,875
      Trade Loan Agreement                                                   5,259                  5,259
      Note to Parent                                                           428                    435
                                                                          --------               -------- 
                                                                           237,432                237,909
      Less Current Maturities                                                5,687                    435
                                                                          --------               --------        
                                                                          $231,745               $237,474
                                                                          ========               ======== 
</TABLE>




NOTE E -- ENVIRONMENTAL MATTERS

Environmental legislation and regulation at both the federal and state level is
subject to change, which may change the cost of compliance. Various possible
methods of remediation are presently being studied for approval; however, it is
expected that the investigation and remediation process will take a number of
years. Although the ultimate costs associated with the remediation are not
presently known, the Company has estimated the cost to be approximately $12.2
million with these costs recorded in accrued liabilities as of June 30, 1997.
The Company paid approximately $5.2 million in remediation costs in fiscal 1997.
Of the amount accrued at March 31, 1997, the Company expects to pay
approximately $5.1 million in fiscal 1998. The timing of future payments are
uncertain due to the various remediation alternatives being considered. The
Company's estimate of the remediation costs is based on its review of each site
and the nature of such problems. The Company then determines for each site the
expected remediation methods, and the estimated cost for each step of
remediation. In all such determinations, the Company employs outside
consultants, and providers of such remedial services where necessary, to assist
in making such determinations.





                                      7
<PAGE>   8


AMERISTEEL CORPORATION
NOTES TO FINANCIAL STATEMENTS

NOTE E -- ENVIRONMENTAL MATTERS - continued

The Company expensed approximately $2 million in each of the past two fiscal
years, and $6 million in fiscal 1995 for environmental remediation costs.

Based on past use of certain technologies and remediation methods by third
parties, evaluation of those technologies and methods by the Company's
consultants and quotations and third-party estimates of costs of
remediation-related services provided to the Company or of which the Company and
its consultants are aware, the Company and its consultants believe that the
Company's cost estimates are reasonable. In light of the uncertainties inherent
in determining the costs associated with the clean-up of such contamination,
including the time periods over which such costs must be paid, the extent of
contribution by parties which are jointly and severally liable, and the nature
and timing of payments to be made under cost sharing arrangements, there can be
no assurance the ultimate costs of remediation may not be greater or less than
the estimated remediation costs.

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

FACTORS THAT MAY AFFECT OPERATING RESULTS

The statements in this report that are not purely historical are forward looking
statements within the meaning of section 27A of the Securities Act of 1933 and
section 21E of the Securities Exchange Act of 1934, including statements
regarding the Company's expectations, hopes, intentions, or strategies regarding
the future. All forward looking statements made by the Company involve a number
of inherent risks and uncertainties which could cause actual results to differ
materially. These risks and uncertainties include economic and general business
conditions, most notably construction levels in the Company's market area;
competitive factors including pricing decisions; raw material availability and
price fluctuations; and other significant activities, to name a few.

LIQUIDITY AND CAPITAL RESOURCES

The Company recently extended the maturity of its Revolving Credit Agreement by
one year to June 9, 1999. The Revolving Credit Agreement provides up to $140
million in borrowings subject to a "borrowing base" amount which substantially
provides the Company's liquidity. Available funding under the Revolver was $33.2
million at June 30, 1997.

Net cash provided by operating activities for the quarter ended June 30, 1997
was $5.1 million compared to $18.4 million for the same period last year, due
primarily to increased working capital levels as a result of improved production
and sales activities. Accounts receivables increased $9.4 million during the
quarter ended June 30, 1997 while inventories declined by $1.3 million. Finished
goods inventory increased by $1.9 million but was offset by a $3.2 million
reduction in work-in-process and raw material inventories.

The Company believes that the amounts available from operating cash flows and
funds available through its Revolving Credit Agreement are sufficient to meet
its expected cash needs and planned capital expenditures for the foreseeable
future.

The Company continues to comply with all of the covenants of its loan
agreements.



                                      8
<PAGE>   9


AMERISTEEL CORPORATION
ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
         AND RESULTS OF OPERATION - Continued

<TABLE>
<CAPTION>
RESULTS OF OPERATIONS                                        THREE MONTHS ENDED
                                                           JUNE 30,     JUNE 30,
                                                             1997         1996
                                                          (UNAUDITED) (UNAUDITED)
                                                          ----------- ----------- 

<S>                                                        <C>          <C>         
Shipments (Tons)                                                                     
----------------
Stock Rebar                                                 140,261      134,635     
Merchant Bar                                                136,093      120,784     
Rods                                                         29,029       35,398     
                                                           --------     --------     
       Mill Finished Products                               305,383      290,817     
                                                            
                                                                                     
Fabricated Rebar                                             85,327       84,019     
Billets                                                      55,335      108,564     
                                                           --------     --------     
Total Shipments                                             446,045      483,400     
                                                           ========     ========     
                                                                                     
Selling Price ($ Per Ton)                                                            
-------------------------
Stock Rebar                                                $    331     $    308
Merchant Bar                                                    364          357     
Rods                                                            339          319     
                                                           --------     --------     
       Mill Finished Products                                   346          329     
Fabricated Rebar (plain)                                        457          453     
Billets                                                         231          222     
                                                          
                                                                                     
Metal Margin Spread ($ Per Ton)                                                      
-------------------------------
Mill Selling Price                                         $    346     $    329     
Ferrous Scrap Price                                             129          131     
                                                           --------     --------        
Metal Margin Spread                                        $    217     $    198          
                                                           ========     ========     
</TABLE>


Revenues: Improved market conditions resulted in a 4.2% increase in shipments of
finished goods coupled with a 5.2% increase in average mill selling prices for
the first fiscal quarter ended June 30, 1997 compared with the same period last
year. While overall revenues declined 1%, the ratio of higher margin finished
product sales to semi-finished billet shipments improved. Full utilization of
the Company's Charlotte, North Carolina and Jackson, West Tennessee rolling
mills, where production of finished goods was curtailed by major projects last
year, improved inventory availability.

Cost of Sales: Higher and more efficient production levels, lower scrap costs
and improved ratio of finished goods to billet sales resulted in cost of sales
declining from 88% of net sales in the quarter ended June 30, 1996 to 80% of
sales in the quarter ended June 30, 1997.

Selling and Administrative: Selling and administrative expenses for the quarter
ended June 30, 1997 increased 9.2% over the same period last year due primarily
to increased incentive pay as a result of improved performance.

Depreciation: Depreciation expense of $4.8 million for the quarter ended June
30, 1997 increased 20.8% over the same period last year due to capital
improvement spending of $23.8 million since June 30, 1996.



                                      9
<PAGE>   10



                         PART II -- OTHER INFORMATION

ITEM 6.       EXHIBITS AND REPORTS ON FORM 8-K

              (a) The following documents are filed as exhibits to this 
                  Quarterly Report on Form 10-Q:

                  Exhibit 11    Statement re: computation of per share earnings
                  Exhibit 27    Financial Data Schedule (for SEC use only)

              (b) Reports on Form 8-K:

                  None

                                    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.

                                    AMERISTEEL CORPORATION


Date: August 4, 1997                /s/  Phillip E. Casey
                                    --------------------------------------------
                                    Phillip E. Casey, Chairman of the Board and 
                                    Chief Executive Officer


Date: August 4, 1997                /s/  Tom J. Landa
                                    --------------------------------------------
                                    Tom J. Landa, Vice President, Chief 
                                    Financial Officer and Secretary (Principal 
                                    Financial Officer and Principal Accounting 
                                    Officer); Director



                                      10