<PAGE>   1
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                  --------------------------------------------


                                 FORM 10-QSB/A

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

         For the quarterly period ended September 30, 1998

                                     OR

[ ]      TRANSITION REPORT UNDER SECTION 13 OR 15 (D) OF THE  
         SECURITIES EXCHANGE ACT OF 1934


        FOR THE TRANSITION PERIOD FROM ______________ to _______________

                         Commission File Number 0-24898

                               MSB FINANCIAL, INC.
             (Exact name of registrant as specified in its charter)


         MARYLAND                                      38-3203510           
         --------                                      ----------           
(State or other jurisdiction of              (I.R.S. Employer Identification
incorporation or organization                Number)

PARK AND KALAMAZOO AVENUE, N.E., MARSHALL, MICHIGAN                49068   
---------------------------------------------------                -----   
(Address of principal executive offices)                          (ZIP Code)

Registrant's telephone number, including area code:     (616) 781-5103

         Check 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 [ ]

As of November 6, 1998, there were 1,319,641 shares of the Registrant's common
stock issued and outstanding.



Transitional Small Business Disclosure Format (check one)

Yes [ ]       No [X]


<PAGE>   2



         The following is an amended quarterly report on Form 10-QSB for the
         period ended September 30, 1998.  Due to an accounting error basic and 
         fully diluted earnings were reported incorrectly at $0.26 per share and
         $0.25 per share, respectively.  The report has been amended to reflect 
         the correct basic and fully diluted earnings values of $0.23 per share 
         and $0.22 per share, respectively.
<PAGE>   3


                               MSB FINANCIAL, INC.

                                      INDEX
<TABLE>
<S>                                                                    <C>
PART I.  FINANCIAL INFORMATION ...................................      1

Item 1.  Financial Statements (Unaudited).........................      1

Consolidated Condensed Statements of Financial Condition .........      1
Consolidated Condensed Statements of Income ......................      2
Consolidated Condensed Statements of Shareholders' Equity ........      3
Consolidated Condensed Statements of Cash Flows ..................      4
Notes to Consolidated Condensed Financial Statements .............      5

Item 2.  Management's Discussion and Analysis of Financial
         Condition and Results of Operations .....................      6-9

PART II. OTHER INFORMATION........................................      10

         SIGNATURES...............................................      11

         EXHIBIT INDEX............................................      12
</TABLE>


<PAGE>   4
                                                                   
                      CONSOLIDATED CONDENSED STATEMENTS OF
                              FINANCIAL CONDITION
                      September 30, 1998 and June 30, 1998

--------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                                                   September 30,         June 30,
                                                                                     1998                   1998
                                                                                     ----                   ----
                                                                                   (Unaudited)
<S>                                                                             <C>                <C>
ASSETS
     Cash and due from financial institutions                                   $     1,657,496    $      2,286,520
     Interest-bearing deposits                                                        1,029,709             994,193
                                                                                ---------------    ----------------
         Total cash and cash equivalents                                              2,687,205           3,280,713

     Securities held to maturity (fair value of $7,088 at
       September 30, 1998 and $8,102 at June 30, 1998)                                    7,088               8,102
     Loans held for sale                                                              1,521,466             295,300
     Loans receivable, net of allowance for loan losses of
       $409,661 at September 30, 1998 and $391,148 at June 30, 1998                  74,145,702          73,065,017
     Federal Home Loan Bank stock                                                     1,176,900           1,158,200
     Accrued interest receivable                                                        471,115             419,847
     Premises and equipment, net                                                        658,717             648,878
     Mortgage servicing rights                                                          215,321             177,006
     Other assets                                                                       922,841             913,650
                                                                                ---------------    ----------------

         Total Assets                                                           $    81,806,355    $     79,966,713
                                                                                ===============    ================

LIABILITIES AND SHAREHOLDERS' EQUITY
Liabilities
     Deposits                                                                   $    43,586,452    $     42,815,148
     Federal Home Loan Bank Advances                                                 23,537,195          21,971,976
     Advance payments by borrowers for taxes and insurance                              392,891             524,739
     Accrued interest payable                                                            93,213              93,114
     Accrued expenses and other liabilities                                             693,607           1,249,043
                                                                                ---------------    ----------------
              Total Liabilities                                                      68,303,358          66,654,020

Shareholders' equity
     Preferred stock, $.01 par value:  2,000,000 shares
       authorized; none outstanding
     Common stock, par value $.01: 4,000,000 shares authorized; 1,631,315 
       shares issued and 1,332,941 shares outstanding at September 30, 1998 and
       1,631,315 shares issued and 1,338,051 shares outstanding at 
       June 30, 1998                                                                     16,313              16,313
     Additional paid-in capital                                                       9,577,842           9,533,274
     Retained earnings, substantially restricted                                      7,160,846           6,970,925
     Unallocated Employee Stock Ownership Plan shares                                  (302,980)           (318,181)
     Unearned Recognition and Retention Plan shares                                    (131,389)           (146,728)
     Less cost of Common Stock in Treasury - 298,374 shares at
       September 30, 1998 and 293,264 shares at June 30, 1998                        (2,817,635)         (2,742,910)
                                                                                ---------------    ----------------
              Total Shareholders' Equity                                             13,502,997          13,312,693 
                                                                                ---------------    ----------------

         Total Liabilities & Shareholders' Equity                               $    81,806,355    $     79,966,713
                                                                                ===============    ================

</TABLE>

--------------------------------------------------------------------------------

     See accompanying notes to consolidated condensed financial statements
                                       1


<PAGE>   5
                        CONSOLIDATED CONDENSED STATEMENTS
                                   OF INCOME
                 Three months ended September 30, 1998 and 1997
                                   (Unaudited)

-------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                                                             Three Months
                                                                                             ------------
                                                                                       1998               1997
                                                                                       ----               ----
<S>                                                                               <C>               <C>
Interest and dividend income
     Loans receivable, including fees                                             $    1,623,959    $     1,539,707
     Securities held to maturity                                                             125                190
     Other interest and dividend income                                                   49,518             47,588
                                                                                  --------------    ---------------
                                                                                       1,673,602          1,587,485
Interest expense
     Deposits                                                                            402,941            391,609
     Federal Home Loan Bank advances                                                     363,383            321,521
     Other interest expense                                                                3,435              2,201
                                                                                  --------------    ---------------
                                                                                         769,759            715,331
                                                                                  --------------    ---------------

NET INTEREST INCOME                                                                      903,843            872,154

Provision for loan losses                                                                 18,000             25,000
                                                                                  --------------    ---------------

NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES                                      885,843            847,154

Noninterest income
     Loan servicing fees, net                                                             19,767             21,106
     Net gain on sales of loans held for sale                                             76,916             42,588
     Service charges on deposit accounts                                                  43,562             34,604
     Profit on sale of real estate owned                                                                     10,666
     Other income                                                                         44,162             32,720
                                                                                  --------------    ---------------
                                                                                         184,407            141,684
Noninterest expense
     Salaries and employee benefits                                                      262,524            245,223
     Occupancy and equipment expense                                                      68,184             50,035
     Data processing expense                                                              47,703             43,614
     Year 2000 expense                                                                     8,576
     Federal deposit insurance premium                                                    13,312             12,942
     Director fees                                                                        29,497             30,472
     Correspondent bank charges                                                           14,134             14,399
     Michigan Single Business tax                                                         17,000             18,000
     Advertising expense                                                                  30,520             19,686
     Professional fees                                                                    44,390             24,399
     Supplies expense                                                                     17,861             13,319
     Other                                                                                72,727             67,229
                                                                                  --------------    ---------------
                                                                                         626,428            539,318
                                                                                  --------------    ---------------

INCOME BEFORE FEDERAL INCOME TAX EXPENSE                                                 443,822            449,520

Federal income tax expense                                                               159,000            159,000
                                                                                  --------------    ---------------

NET INCOME                                                                        $      284,822    $       290,520
                                                                                  ==============    ===============

Basic earnings per share                                                          $         0.23    $          0.26
                                                                                  ==============    ===============

Weighted average common shares outstanding                                             1,247,125          1,131,956
                                                                                  ==============    ===============

Diluted earnings per share                                                        $         0.22    $          0.25
                                                                                  ==============    ===============

Weighted average common and diluted
  potential common shares outstanding                                                  1,299,783          1,170,102
                                                                                  ==============    ===============

</TABLE>

--------------------------------------------------------------------------------

           See accompanying notes to consolidated condensed financial statements
                                       2

<PAGE>   6
                               
          CONSOLIDATED CONDENSED STATEMENTS OF SHAREHOLDERS' EQUITY
                Three months ended September 30, 1998 and 1997
                                 (Unaudited)
--------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                                                               Unallocated    
                                                                      Additional              Employee Stock  
                                                      Common           Paid-In      Retained     Ownership    
                                                      Stock           Capital       Earnings    Plan Shares   
                                                      -----           -------       --------   -----------    
<S>                                                <C>            <C>            <C>           <C>         
BALANCE, JULY 1, 1997                              $    14,830    $ 7,096,776    $ 8,372,493   $  (383,006)

Net income                                                                           290,520        

Shares committed to be released (3,564 shares)
  under the Employee Stock Ownership Plan (ESOP)                       33,479                       16,200         

Shares earned under the RRP                                                        

Cash dividends declared on common stock, net
  of dividends on unallocated ESOP Shares                                            (80,991)       

Repurchase of 15,000 shares of Common Stock           
                                                   -----------    -----------    -----------   -----------
BALANCES, SEPTEMBER 30, 1997                       $    14,830    $ 7,130,255    $ 8,582,022   $  (366,806)
                                                   ===========    ===========    ===========   ===========

BALANCES, JULY 1, 1998                             $    16,313    $ 9,533,274    $ 6,970,925   $  (318,181)

Net income                                                                           284,822      

Shares committed to be released (3,506 shares)
  under the Employee Stock Ownership Plan (ESOP)                       44,799                       15,201         

Shares earned under the RRP                                                               

Cash dividends declared on common stock, net
  of dividends on unallocated ESOP shares                                            (94,901)       

Repurchase of 5,110 shares of Common Stock             

Payment of Fractional shares on 10% Dividend                             (231)         
                                                   -----------    -----------    -----------   -----------

BALANCES, SEPTEMBER 30, 1998                       $    16,313    $ 9,577,842    $ 7,160,846   $  (302,980)
                                                   ===========    ===========    ===========   ===========
                                                  
</TABLE>

<TABLE>
<CAPTION>
                                                    Unearned                                          
                                                   Recognition       Common            Total        
                                                  and Retention     Stock in       Shareholders'    
                                                  Plan Shares       Treasury          Equity        
                                                  -----------       --------          ------         
<S>                                                <C>            <C>            <C>        
BALANCE, JULY 1, 1997                              $  (208,084)   $ (2,202,813)  $12,690,196

Net income                                                                           290,520                                 

Shares committed to be released (3,564 shares)
  under the Employee Stock Ownership Plan (ESOP)                                      49,679

Shares earned under the RRP                             15,339                        15,339                    

Cash dividends declared on common stock, net
  of dividends on unallocated ESOP Shares                                            (80,991)     

Repurchase of 15,000 shares of Common Stock                           (225,000)     (225,000)    
                                                   -----------    ------------   -----------

BALANCES, SEPTEMBER 30, 1997                       $  (192,745)   $ (2,427,813)  $12,739,743
                                                   ===========    ============   ===========


BALANCES, JULY 1, 1998                             $  (146,728)   $ (2,742,910)  $13,312,693

Net income                                                                           284,822

Shares committed to be released (3,506 shares)
  under the Employee Stock Ownership Plan (ESOP)                                      60,000

Shares earned under the RRP                             15,339                        15,339                     

Cash dividends declared on common stock, net
  of dividends on unallocated ESOP shares                                            (94,901)

Repurchase of 5,110 shares of Common Stock                             (74,725)      (74,725) 


Payment of Fractional shares on 10% Dividend                                            (231)
                                                   -----------    ------------   -----------

BALANCES, SEPTEMBER 30, 1998                       $  (131,389)   $ (2,817,635)  $13,502,997
                                                   ===========    ============   ===========

</TABLE>
                                        

--------------------------------------------------------------------------------

      See accompanying notes to consolidated condensed financial statements
                                        3
<PAGE>   7

                 CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                 Three months ended September 30, 1998 and 1997
                                   (Unaudited)

--------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                                                           1998              1997
                                                                                           ----              ----
<S>                                                                                <C>              <C>            
CASH FLOWS FROM OPERATING ACTIVITIES
     Net income                                                                    $      284,822   $       290,520
     Adjustments to reconcile net income
       to net cash from operating activities
         Provision for loan losses                                                         18,000            25,000
         Depreciation                                                                      34,537            21,633
         Amortization of mortgage servicing rights                                          7,335               436
         Employee Stock Ownership Plan expense                                             60,000            49,679
         Recognition and Retention Plan expense                                            15,339            15,339
         Originations of loans held for sale                                           (5,791,225)       (2,781,527)
         Proceeds from sales of loans held for sale                                     4,596,325         2,367,900
         Net gains on sales of loans held for sale                                        (76,916)          (42,588)
         Change in assets and liabilities
              Accrued interest receivable                                                 (51,268)          (24,697)
              Other assets                                                                 (9,191)           28,510
              Accrued interest payable                                                         99            10,839
              Other expense and other liabilities                                        (555,436)          273,880
                                                                                   --------------   ---------------
                  Net cash from operating activities                                   (1,467,579)          234,924

CASH FLOWS FROM INVESTING ACTIVITIES
     Principal paydowns on mortgage-backed securities                                       1,014               846
     Purchase of FHLB stock                                                               (18,700)          (19,400)
     Net increase in loans                                                             (1,098,685)       (1,249,058)
     Net purchases of premises and equipment                                              (44,376)          (11,528)
                                                                                   --------------   --------------- 
         Net cash used in investing activities                                         (1,160,747)       (1,279,140)

CASH FLOWS FROM FINANCING ACTIVITIES
     Net increase in deposits                                                             771,304           218,718
     Proceeds from Federal Home Loan Bank advances                                      4,000,000         8,000,000
     Repayments on Federal Home Loan Bank advances                                     (2,434,781)       (6,112,891)
     Decrease in advance payments
         by borrowers for taxes and insurance                                            (131,848)         (123,798)
     Payment of dividends on common stock                                                 (95,132)          (80,991)
     Repurchase of common stock                                                           (74,725)         (225,000)
                                                                                   --------------   --------------- 
         Net cash from financing activities                                             2,034,818         1,676,038
                                                                                   --------------   ---------------

Net change in cash and cash equivalents                                                  (593,508)          631,822

Cash and cash equivalents at beginning of period                                        3,280,713         3,080,612
                                                                                   --------------   ---------------

CASH AND CASH EQUIVALENTS AT END OF PERIOD                                         $    2,687,205   $     3,712,434
                                                                                   ==============   ===============

Supplemental disclosures of cash flow information 
     Cash paid during the period for:
         Interest                                                                  $      769,661   $       702,292
         Income taxes                                                                                        25,956

</TABLE>

--------------------------------------------------------------------------------

     See accompanying notes to consolidated condensed financial statements.

                                        4


<PAGE>   8

                               MSB FINANCIAL, INC.
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                      Three months ended September 30,1998
                                   (Unaudited)

--------------------------------------------------------------------------------

NOTE 1 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

The accompanying consolidated condensed financial statements include the
accounts of MSB Financial, Inc. (the "Company") and its wholly-owned subsidiary,
Marshall Savings Bank, F.S.B. ("Bank") after the elimination of significant
intercompany transactions and accounts. The initial capitalization of the
Company and its acquisition of the Bank took place on February 6, 1995.

These interim financial statements are prepared in accordance with the
Securities and Exchange Commission's rules for quarterly financial information
without audit and reflect all adjustments which, in the opinion of management,
are necessary to present fairly the financial position of the Company at
September 30, 1998 and the results of its operations and its cash flows for the
periods presented. All such adjustments are normal and recurring in nature. The
accompanying consolidated condensed financial statements do not purport to
contain all the necessary disclosures required by generally accepted accounting
principles that might otherwise be necessary in the circumstances and should be
read in conjunction with the consolidated financial statements and notes thereto
included in the annual report of MSB Financial, Inc. for the year ended June 30,
1998. The results of the periods presented are not necessarily representative of
the results of operations and cash flows which may be expected for the entire
year.

The provision for income taxes is based upon the effective tax rate expected to
be applicable for the entire year.

Basic and diluted earnings per share for the periods presented in 1998 and 1997
were computed under a new accounting standard effective in the quarter ended
December 31, 1997. All prior amounts have been restated to be comparable. Basic
earnings per share is based on net income divided by the weighted average number
of common shares outstanding during the period, adjusted for Employee Stock
Ownership Plan (ESOP) shares not committed for release and Recognition and
Retention Plan (RRP) shares not yet vested. Diluted earnings per share shows the
dilutive effect of additional common shares issuable under stock option plans.
Net income was $284,822 for the three month period ended September 30, 1998. The
weighted average number of common shares outstanding for the three month period
ended September 30, 1998 was 1,247,125. The weighted average of number of common
and diluted potential common shares outstanding for the three month period ended
September 30, 1998 was 1,299,783. Net income was $290,520 for the three month
period ended September 30, 1997. The weighted average number of common shares
outstanding for the three month period ended September 30, 1997 was 1,131,956.
The weighted average of number of common and diluted potential common shares
outstanding for the three month period ended September 30, 1997 was 1,170,102.

NOTE 2 - REPURCHASES OF COMMON STOCK

During the quarter ended September 30, 1998, the Company repurchased 5,110
shares of its common stock at a total cost of $74,725, or $14.62 per share, as
compared to 16,500 shares during the quarter ended September 30, 1997 at a total
cost of $225,000 or $13.64 per share. The Company is currently in the process of
repurchasing an additional 5%, or 67,738 shares of its common stock and as of
September 30, 1998 had repurchased 21,830 shares under this program. Approval to
repurchase the remaining 45,908 shares expires on February 11, 1999. As of
September 30, 1998, a total of 298,374 shares of the Company's common stock had
been repurchased at a total cost of $2,817,635, or $9.44 per share.

--------------------------------------------------------------------------------


                                       5
<PAGE>   9



         Pursuant to the requirement 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.

                                   SIGNATURES

                                           MSB FINANCIAL, INC.
                                           Registrant


Date: December 22, 1998                    \s\Charles B. Cook               
                                           ------------------
                                           Charles B. Cook, President and Chief
                                           Executive Officer  (Duly Authorized
                                           Officer)

Date: December 22, 1998                    \s\Elaine R. Carbary
                                           --------------------
                                           Elaine R. Carbary, Chief Financial
                                           Officer (Principal Financial Officer)



                                       11
<PAGE>   10


                               MSB FINANCIAL, INC.

                                  EXHIBIT INDEX

Exhibit No.                Description                             Page No.
-----------                -----------                             --------

     27                    Financial Data Schedule                    13






                                       12