<PAGE>   1

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 10-Q/A

                                AMENDMENT NO. 1 to

(X)      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For The Quarterly Period Ended September 30, 1997
                                        ------------------

                                       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 Number 000-21786
                       ---------


                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.
       -------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)



    STATE OF DELAWARE                                    57-0962375
------------------------------------------  ------------------------------------
    (State or other jurisdiction of         (I.R.S. Employer Identification No.)
    incorporation or organization)


    7909 Parklane Road,  Columbia, SC                       29223
------------------------------------------  ------------------------------------
    (Address of Principal Executive Office)               (Zip Code)


Registrant's telephone number, including area code   (803)741-3000
                                                  ------------------------------

Indicate by check mark whether the registrant 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 each shorter period that the registrant was
required to file reports) and has been subject to such filing requirements for
the past 90 days.

YES     X          NO
     -------           ------

The number of shares of common stock of the Registrant outstanding as of October
31, 1997, was 20,320,046 (21,336,048 after giving effect to the 5% stock
dividend declared on October 31, 1997).



                                     Page 1


<PAGE>   2



                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.
               Form 10-Q/A for the quarter ended September 30, 1997

               TABLE OF CONTENTS OF INFORMATION REQUIRED IN REPORT


<TABLE>
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>         <C>                                                            <C>
PART I.     FINANCIAL INFORMATION
-------     --------------------- 

Item 1.     Financial Statements - (Unaudited)
-------     ----------------------------------
            Consolidated Balance Sheet                                       3


            Consolidated Statement of Income                                 4


            Consolidated Statement of Changes in Stockholders' Equity        5


            Consolidated Statement of Cash Flows                             6


            Notes to Consolidated Financial Statements                       7

SIGNATURES                                                                  10
----------
</TABLE>





                                        2


<PAGE>   3
                        PART I. FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.
                           CONSOLIDATED BALANCE SHEET
                                ($ in thousands)



<TABLE>
<CAPTION>
                                                          September 30,     December 31,
                                                              1997              1996
                                                          -------------     ------------
ASSETS                                                     (Unaudited)

<S>                                                       <C>               <C>        
Cash                                                      $     8,939       $     2,492
Residual certificate                                            7,550
Receivables                                                    96,882            60,668
Mortgage-backed securities                                    196,675           123,447
Mortgage loans held for sale                                  893,656           678,888
Mortgage servicing rights, net                                128,713           109,815
Premises and equipment, net                                    24,287            21,135
Goodwill and other intangibles                                  8,221
Accrued interest on loans held for sale                         4,004             4,491
Other assets                                                   35,217            27,458
                                                          -----------       -----------

    Total assets                                          $ 1,404,144       $ 1,028,394
                                                          ===========       ===========


LIABILITIES AND STOCKHOLDERS' EQUITY

Liabilities
    Short-term borrowings                                 $ 1,129,065       $   805,730
    Long-term borrowings                                        6,485
    Accrued expenses                                           13,438            11,386
    Other liabilities                                          76,573            53,977
                                                          -----------       -----------

    Total liabilities                                       1,225,561           871,093
                                                          -----------       -----------

Stockholders' equity
    Common stock                                                  210               193
    Additional paid-in capital                                171,151           149,653
    Retained earnings                                          11,190            12,007
    Unearned shares of employee stock ownership plan           (3,968)           (4,552)
                                                          -----------       -----------

    Total stockholders' equity                                178,583           157,301
                                                          -----------       -----------

    Total liabilities and stockholders' equity            $ 1,404,144       $ 1,028,394
                                                          ===========       ===========
</TABLE>


          See accompanying notes to consolidated financial statements.
                                        3

<PAGE>   4
                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.

                        CONSOLIDATED STATEMENT OF INCOME
                   ($ in thousands, except share information)
                                   (Unaudited)



<TABLE>
<CAPTION>
                                                       For the Nine Months Ended           For the Three Months Ended
                                                              September 30,                        September 30,
                                                    -------------------------------      --------------------------------

                                                        1997                1996              1997                1996
                                                    ------------       ------------      -------------       ------------
<S>                                                 <C>                <C>                <C>                <C>         
REVENUES
     Interest income                                $     53,301       $     49,809       $     21,613       $     14,508
     Interest expense                                    (39,115)           (37,029)           (17,078)           (10,008)
                                                    ------------       ------------       ------------       ------------
     Net interest income                                  14,186             12,780              4,535              4,500
     Net gain on sale of mortgage loans                   71,578             59,348             29,328             19,312
     Gain on sale of mortgage servicing rights             5,948                964              3,237                775
     Loan servicing fees                                  23,049             21,379              7,711              7,520
     Other income                                            572                404                146                106
                                                    ------------       ------------       ------------       ------------
          Total revenues                                 115,333             94,875             44,957             32,213
                                                    ------------       ------------       ------------       ------------
EXPENSES
     Salary and employee benefits                         43,631             37,830             16,487             12,315
     Occupancy expense                                     5,328              4,125              1,886              1,485
     Amortization of mortgage servicing rights            13,673             11,064              4,840              3,748
     General and administrative expenses                  29,580             14,608             17,837              4,858
                                                    ------------       ------------       ------------       ------------
          Total expenses                                  92,212             67,627             41,050             22,406
                                                    ------------       ------------       ------------       ------------

     Income before income taxes                           23,121             27,248              3,907              9,807
     Income tax expense                                   (8,713)           (10,340)            (1,340)            (3,626)
                                                    ------------       ------------       ------------       ------------
     Net income                                     $     14,408       $     16,908       $      2,567       $      6,181
                                                    ============       ============       ============       ============

     Weighted average shares (retroactively           20,902,473         18,916,081         21,260,707         19,914,160
     adjusted for the 5% stock dividend declared    ============       ============       ============       ============
     on October 31, 1997)*

     Net income per common share                    $       0.69       $       0.89       $       0.12       $       0.31
                                                    ============       ============       ============       ============
</TABLE>


*        The provisions of Accounting Principles Board Opinion No. 15, "Earnings
         per Share" required that the Company, effective for the first quarter
         of 1997, prospectively commence to report net income per common share
         on a primary earnings per share basis. Accordingly, the weighted
         average shares outstanding for the third quarter of 1997 and the nine
         months ended September 30, 1997 includes common stock equivalents while
         such equivalents are excluded for the comparable periods of the prior
         year.







          See accompanying notes to consolidated financial statements.
                                        4

<PAGE>   5
                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.

            CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY
                   ($ in thousands, except share information)
                                   (Unaudited)


<TABLE>
<CAPTION>
                                                                                             Unearned 
                                          Common Stock          Additional                Shares of Employee
    Nine Months Ended               -----------------------      Paid-in      Retained     Stock Ownership
    September 30, 1996                Shares         Amount      Capital      Earnings         Plan           Total
---------------------------         ----------     ---------    ---------    ----------      ---------       --------
<S>                                 <C>            <C>          <C>          <C>             <C>             <C>     
Balance, December 31, 1995          14,550,462      $ 146       $ 84,533      $ 10,725       $ (2,000)       $ 93,404

Issuance of restricted stock            16,410          *            256                                          256
Net proceeds of public offering      3,426,552         34         47,417                                       47,451
Stock dividend adjustment            1,261,332         13         17,115       (17,128)
Cash dividend                                                                     (542)                          (542)
Shares committed to be                                                                            
    released under ESOP                                              111                          300             411
Shares issued under Dividend
    Reinvestment and Stock
    Purchase Plan and Stock                                                                                             
    Investment Plan                     25,107          *            157                                          157
Loans to ESOP                                                                                  (2,365)         (2,365)
Net income                                                                      16,908                         16,908
                                    ----------      -----       --------      --------       --------        --------
Balance, September 30, 1996         19,279,863      $ 193       $149,589      $  9,963       $ (4,065)       $155,680
                                    ==========      =====       ========      ========       ========        ========
</TABLE>



<TABLE>
<CAPTION>
                                                                                            Unearned       
                                          Common Stock         Additional               Shares of Employee 
    Nine Months Ended               ----------------------      Paid-in      Retained     Stock Ownership  
    September 30, 1997               Shares        Amount       Capital      Earnings         Plan            Total    
---------------------------         ----------    --------     ---------     --------       --------         ------- 

<S>                                 <C>           <C>          <C>           <C>            <C>              <C>     
Balance, December 31, 1996          19,285,020      $ 193       $149,653      $12,007        $(4,552)        $157,301

Issuance of restricted stock            23,528          *            328                                          328
Cash dividends                                                                 (1,739)                         (1,739)
Acquisition of Meritage Mortgage
    Corporation                        673,197          6          7,162                                        7,168
Exercise of stock options               62,000          1            379                                          380
Shares committed to be            
    released under ESOP                                              213                         584              797
Shares issued under Dividend
    Reinvestment and Stock
    Purchase Plan and Stock
    Investment Plan                      5,599          *             18          (78)                            (60)
Retroactive adjustment for the 5%        
    stock dividend declared on
    October 31, 1997                 1,002,467         10         13,398      (13,408)
Net income                                                                     14,408                          14,408
                                    ----------      -----       --------      -------        -------         --------

Balance, September 30, 1997         21,051,811      $ 210       $171,151      $11,190        $(3,968)        $178,583
                                    ==========      =====       ========      =======        =======         ========
</TABLE>




* Amount less than $1

















          See accompanying notes to consolidated financial statements.
                                        5

<PAGE>   6

                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.

                      CONSOLIDATED STATEMENT OF CASH FLOWS
                                ($ in thousands)
                                   (Unaudited)

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
                                                                                                   Nine Months Ended September 30,
                                                                                                     1997                  1996
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                                                 <C>                 <C>     
OPERATING ACTIVITIES:
    Net income                                                                                      $   14,408            $ 16,908
    Adjustments to reconcile net
       income to cash (used in) provided by operating activities:
       Depreciation and amortization                                                                    16,191              12,980
       Employee Stock Ownership Plan compensation                                                          797                 291
       Provision for estimated foreclosure losses                                                        2,605
       Increase in receivables                                                                         (36,214)             (1,451)
       Acquisition of mortgage loans                                                                (7,799,804)         (7,928,301)
       Proceeds from sales of mortgage loans and mortgage-backed securities                          7,583,386           8,279,643
       Acquisition of mortgage servicing rights                                                       (175,232)           (174,941)
       Sales of mortgage servicing rights                                                              146,004             157,532
       Net gain on sales of mortgage loans and servicing rights                                        (77,526)            (60,312)
       Decrease in accrued interest on loans                                                               487               4,757
       Increase in other assets                                                                         (6,679)             (8,948)
       Increase in residual certificates                                                                (7,550)
       Increase in accrued expenses and other liabilities                                               24,648               3,162
-----------------------------------------------------------------------------------------------------------------------------------
              Net cash (used in) provided by operating activities                                     (314,479)            301,320
-----------------------------------------------------------------------------------------------------------------------------------

INVESTING ACTIVITIES:
    Purchases of premises and equipment, net                                                            (5,500)             (6,587)
-----------------------------------------------------------------------------------------------------------------------------------
              Net cash used in investing activities                                                     (5,500)             (6,587)
-----------------------------------------------------------------------------------------------------------------------------------

FINANCING ACTIVITIES:
    Proceeds from borrowings                                                                        20,666,472          25,933,824
    Repayment of borrowings                                                                        (20,336,652)        (26,272,671)
    Issuance of restricted stock                                                                           328                 256
    Shares issued under Dividend Reinvestment and Stock Purchase Plan
      and Stock Investment Plan                                                                            (60)                157
    Acquisition of Meritage Mortgage Corporation                                                        (1,750)
    Debt issuance costs                                                                                   (553)
    Cash dividends                                                                                      (1,739)               (542)
    Net proceeds of public offering                                                                                         47,451
    Exercise of stock options                                                                              380
    Loans to Employee Stock Ownership Plan                                                                                  (1,954)
-----------------------------------------------------------------------------------------------------------------------------------
              Net cash provided by (used in) financing activities                                      326,426            (293,479)
-----------------------------------------------------------------------------------------------------------------------------------

Net increase in cash                                                                                     6,447               1,254
Cash, beginning of period                                                                                2,492               2,161
-----------------------------------------------------------------------------------------------------------------------------------
Cash, end of period                                                                                    $ 8,939             $ 3,415
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>









          See accompanying notes to consolidated financial statements.
                                        6


<PAGE>   7


                    RESOURCE BANCSHARES MORTGAGE GROUP, INC.
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997



Note 1 - Basis of Presentation:

     The financial information included herein should be read in conjunction
     with the consolidated financial statements and related notes of Resource
     Bancshares Mortgage Group, Inc. (the Company), included in the Company's
     December 31, 1996, Annual Report on Form 10-K. Certain financial
     information, which is normally included in financial statements prepared in
     accordance with generally accepted accounting principles, is not required
     for interim financial statements and has been omitted. The accompanying
     interim consolidated financial statements are unaudited. However, in the
     opinion of management of the Company, all adjustments, consisting of normal
     recurring items, necessary for a fair presentation of operating results and
     financial position for the periods shown have been made. Certain prior
     period amounts have been reclassified to conform to current period
     presentation.

     In June 1996 the Financial Accounting Standards Board issued Statement of
     Financial Accounting Standards (SFAS) No. 125, "Accounting for Transfers
     and Servicing of Financial Assets and Extinguishments of Liabilities,"
     which is effective for transfers and servicing of financial assets and
     extinguishments of liabilities occurring after December 31, 1996. SFAS No.
     125 is based upon consistent application of a financial-components approach
     that focuses on control. Under this approach, after a transfer of financial
     assets, an entity recognizes the financial and servicing assets it controls
     and the liabilities it has incurred, derecognizes financial assets when
     control has been surrendered, and derecognizes liabilities when
     extinguished. The Company adopted SFAS No. 125 effective January 1, 1997,
     as required. The requirements of SFAS No. 125 are substantially the same as
     those which were previously applicable to the Company pursuant to the
     provisions of SFAS No. 122, "Accounting for Mortgage Servicing Rights-An
     Amendment of FASB Statement No. 65." Accordingly, adoption of SFAS No. 125
     had no material impact on the Company.

     As required by Accounting Principles Board Opinion No. 15, "Earnings per
     Share," the Company has prospectively implemented a policy of reporting
     primary earnings per share effective beginning in the first quarter of
     1997. In February 1997 the Financial Accounting Standards Board issued SFAS
     No. 128, "Earnings per Share", which is effective for financial statements
     issued for periods ending after December 15, 1997. Early adoption of SFAS
     No. 128 is not permitted. Basic and diluted earnings per share for the
     third quarter of 1997 reported pursuant to the provisions of SFAS No. 128
     after retroactive adjustment for a 5% stock dividend declared on October
     31, 1997, would both be $0.12. Basic and diluted earnings per share for the
     first nine months of 1997 reported pursuant to the provisions of SFAS No.
     128 after retroactive adjustment for a 5% stock dividend declared on
     October 31, 1997, would be $0.71 and $0.69, respectively. Adoption of SFAS
     No. 128 should not result in any change in earnings per share for 1996 and
     prior periods.

     Effective April 1, 1997, the Company completed a merger with Meritage
     Mortgage Corporation (Meritage), in which it exchanged approximately
     $1.75 million of cash and 537,846 (564,738 after retroactive adjustment
     for the 5% stock dividend declared on October 31, 1997) noncontingent
     shares of RBMG common stock for all the outstanding stock of Meritage.
     This transaction was accounted for under the purchase method of
     accounting. In addition, 406,053 (426,355 after retroactive adjustment for
     the 5% stock dividend declared on October 31, 1997) shares of RBMG common
     stock were issued contingent upon Meritage achieving specified
     increasingly higher levels of subprime mortgage production during the 31
     months following closing. During the third quarter, 135,351 (142,118 after
     retroactive adjustment for the 5% stock dividend declared on October 31,
     1997) contingent shares of RBMG common stock were released. The fair
     market value of





                                       7
<PAGE>   8

     the remaining contingent shares has been excluded from the purchase price
     for purposes of recording goodwill and from outstanding shares for purposes
     of earnings per share computations. As each specified increasingly higher
     subprime mortgage production level is achieved, the corresponding fair
     market value of the associated contingent shares will be recorded as
     additional goodwill and such shares will prospectively be treated as
     outstanding for purposes of earnings per share computations. The purchase
     price for the Meritage merger has been allocated to tangible and
     identifiable assets and liabilities based upon management's estimate of
     their respective fair values with the excess of estimated cost over the
     fair value of the net assets acquired allocated to goodwill. Goodwill and
     other intangible assets are being amortized over a 20 year period using the
     straight line method. Amortization expense for the third quarter and nine
     month periods ended September 30, 1997 was approximately $103 and $181,
     respectively. In connection with the acquisition, the following is a
     schedule of the allocation of the purchase price:

<TABLE>
<CAPTION>
                                                                                 Release of      Through
                                                            At Acquisition       Contingent      September
                                                            on April 1, 1997       Shares        30, 1997
                                                            ----------------     ----------      ---------
       <S>                                                  <C>                  <C>             <C>              
       Cash paid                                            $  1,750             $      -        $  1,750         
       Estimated fair market value of
        shares of RBMG common stock issued or released         4,748                2,441           7,189         
       Deferred merger cost                                      463                    -             463
                                                            ----------------     ----------      ---------
                                                                     
       Total purchase price                                    6,961                2,441           9,402
       Fair value of net assets acquired                       1,000                    -           1,000
                                                            ----------------     ----------      ---------        
       Goodwill and intangibles                             $  5,961             $  2,441        $  8,402
                                                            ================     ==========      =========         
</TABLE>

     On April 18, 1997 the Company entered into separate definitive merger
     agreements with Resource Bancshares Corporation (RBC) and Walsh Holding
     Co., Inc. (Walsh) pursuant to which the Company, subject to approval by
     shareholders of the Company and satisfaction of other terms and conditions,
     would acquire all  of the outstanding shares of RBC and Walsh.  On November
     3, 1997, the Company and Walsh announced mutual termination of their merger
     agreement. Accordingly, during the third quarter of 1997, the Company
     recorded a $2.3 million ($1.4 million after-tax) charge related
     to joint termination of the Company's merger agreement with Walsh.

     During the second quarter of 1997, the Company sold approximately $107
     million of subprime mortgage loans to Walsh and recognized a gain of
     approximately $3.7 million on those sales.  Approximately $76 million of
     such loans were included in a Walsh securitization which was completed in
     June of 1997.  The remaining loans were expected to be included in Walsh's
     next securitization.  However, during the third quarter the Company
     repurchased the remaining $31 million of loans from Walsh and included 
     those loans in its first subprime securitization transaction which was
     completed on September 29, 1997.  Also during the third quarter, the
     Company advanced approximately $3.8 million to Walsh in connection with
     certain other transactions.  In conjunction therewith at September 30,
     1997, receivables  of approximately $9.9 million are outstanding and due
     from Walsh to the Company.  Such receivables are cross-collateralized and
     secured by an interest in a residual certificate and certain other assets.

     The Company remains committed to completion of its pending merger with RBC.
     RBC, a financial services company, originates and purchases, sells and
     services small-ticket equipment leases through its Republic Leasing Company
     division and originates and services commercial mortgage loans through its
     Laureate subsidiaries.  RBC, as of September 30, 1997, owned approximately
     36% of the Company's common stock.  Pursuant to the terms of the definitive
     merger agreement between RBC and the Company and subject to shareholder and
     regulatory approvals, RBC will merge with the Company in a transaction that
     will be accounted for under the purchase method of accounting.  The
     agreement provides for the Company to issue approximately 2 million
     additional shares of common stock, 2.1 million after giving effect to the
     5% stock dividend declared on October 31, 1997, (in addition to the 7.4
     million shares of Company stock currently owned by RBC, 7.8 million shares
     after giving effect to the 5% stock dividend declared on October 31, 1997)
     to the shareholders of RBC.  As of September 30, 1997 the Company has
     deferred approximately $1.0 million of merger costs related to this
     transaction.

                                       8
<PAGE>   9

     During the third quarter of 1997, the Company recorded a special charge of
     $7.9 million ($4.8 million after-tax) to fully reserve against certain
     unrecoverable receivables. Since recording the special charge, management
     has further reviewed and analyzed the components of the special charge with
     the objective of assessing the affected accounts and determining the time
     periods in which the variances arose. Approximately $6.1 million of the
     charge relates to previously accrued interest income and primarily arose
     during a period beginning in mid-1994 and ending in the second quarter of
     1997. Approximately $0.9 million of the charge represents unrecovered
     servicing advances for interim interest and escrow funds. The variance
     arose during a period beginning in late-1995 and ending in early-1996.
     Approximately $0.9 million of the charge relates to loan discount and
     branch income accruals on retail loan production and arose during a period
     beginning in mid-1995 and ending in mid-1996.

     During 1995 and 1996 the Company's scale of operations grew dramatically.
     The rapid growth outpaced increases in the Company's back-office
     capabilities to timely process activities and research, review, resolve and
     collect on the types of resultant items which ultimately resulted in the
     above summarized variances. 

     Given the nature of these items, management is unable to precisely
     determine the portion of the charge which relates to errors in reported
     income versus valid receivables which have proven uncollectible. However,
     management believes that such items, to the extent they would represent
     errors in reported income of prior periods, are not material to the prior
     periods to which they relate. Management believes its back-office
     processing capabilities are currently appropriate and adequate in relation
     to its current scale of operations. 


                                      9
<PAGE>   10



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.



                     RESOURCE BANCSHARES MORTGAGE GROUP, INC.
                                      (Registrant)




                     Steven F. Herbert
                     ----------------------------
                     Senior Executive Vice President and
                     Chief Financial Officer

                     (signing in the capacity of (i) duly authorized officer of
                     the registrant and (ii) principal financial officer of the
                     registrant)













DATED:   November 26, 1997



                                             10