<PAGE>
                                          
                         SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, D.C.  20549
                                          
                                     FORM 10-Q/A
                                 (AMENDMENT NO. 1)

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

                   For the quarterly period ended November 30, 1998

                                         OR

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

              For the transition period from ___________ to ____________

                               Commission File Number
                                      0-22703


                            GREAT PLAINS SOFTWARE, INC.
               (Exact name of registrant as specified in its charter)


     MINNESOTA                                         45-0374871
(State or other jurisdiction            (I.R.S. Employer Identification No.)
of incorporation or organization)  



1701 S.W. 38TH STREET, FARGO, NORTH DAKOTA               58103
(Address of principal executive offices)               (Zip Code)


                                   (701) 281-0550
                (Registrant's telephone number, including area code)


     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports) and (2) has been subject to such
filing requirements for the past 90 days.

     Yes    X       No     
           ---           ---

     As of December 16, 1998, the number of shares outstanding of the
registrant's Common Stock, par value $.01 per share, was 13,843,309.

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     This amendment is being filed solely for the purpose of filing certain 
exhibits omitted from the original report.

ITEM 6.        EXHIBITS AND REPORTS ON FORM 8-K

(a)  Exhibits

           3.1*  Amended Bylaws of the Company

          10.1   Lease Agreement, dated October 23, 1997, between the Company 
                 and IRET Properties (incorporated by reference to Exhibit 
                 10.18 to the Company's Registration Statement on Form S-1
                 filed March 18, 1998 (SEC File No. 333-48219)).

          10.2   Amendment dated December 21, 1998 to Lease Agreement dated
                 October 1, 1983 between the Company and West Acres Office 
                 Park

          27.1*  Financial Data Schedule

          99.1*  Cautionary Statements

          ------------------
          *Previously filed.

   (b)    Reports on Form 8-K

   No reports on Form 8-K were filed during the quarter ended November 30, 
1998.

                                        -2-

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                                     SIGNATURES

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

Date: February 4, 1999

                    GREAT PLAINS SOFTWARE, INC.



                         By /s/ Terri F. Zimmerman
                            --------------------------------------------------
                         Terri F. Zimmerman  
                         Chief Financial Officer and Executive Vice President
                         (principal financial and accounting officer)

                                        -3-

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                                   EXHIBIT INDEX


      3.1*  Amended Bylaws of the Company

     10.1   Lease Agreement, dated October 23, 1997, between the Company 
            and IRET Properties (incorporated by reference to Exhibit 
            10.18 to the Company's Registration Statement on Form S-1
            filed March 18, 1998 (SEC File No. 333-48219)).

     10.2   Amendment dated December 21, 1998 to Lease Agreement dated
            October 1, 1983 between the Company and West Acres Office 
            Park

     27.1*  Financial Data Schedule

     99.1*  Cautionary Statements

     ------------------
     *Previously filed.
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