Page 25
                                                             Exhibit 10(iii)A(6)

                               AMENDMENT NO. 1 TO
                        NATIONAL SERVICE INDUSTRIES, INC.
                  NONEMPLOYEE DIRECTOR DEFERRED STOCK UNIT PLAN



     This  Amendment is made as of the 23rd day of September,  1997, by National
Service Industries, Inc. (the "Corporation").

                              W I T N E S S E T H:

     WHEREAS,  the  Corporation  previously  established  the  National  Service
Industries,  Inc. Nonemployee Director Deferred Stock Unit Plan (the "Plan") for
the  benefit  of  directors  of the  Corporation  who are not  employees  of the
Corporation or any Subsidiary (as defined in the Plan); and

     WHEREAS, pursuant to the power of amendment contained in Section 7.1 of the
Plan, by action of the Board of Directors of the Corporation on the date hereof,
the Plan is hereby amended as follows:

                                       1.

     Paragraph  2.1(e) of the Plan is  amended,  effective  January 8, 1997,  by
deleting  the existing  language  thereof and  substituting  in lieu thereof the
following:  "`Committee'  shall mean the  Executive  Resource  and  Compensation
Committee."
                                       2.

     Paragraph  2.1 (o) of the Plan is amended,  effective  December 1, 1997, by
deleting  the existing  language  thereof and  substituting  in lieu thereof the
following: "`Required Amount' shall mean one-half of the Annual Fee."

                                       3.

     Article  5  of  the  Plan  is  amended,  effective  December  1,  1997,  by
renumbering  Section 5.3 as 5.5 and  inserting the following as Sections 5.3 and
5.4:

     5.3  Annual Grant.  On the first day of each December on and after December
          1, 1997 and prior to the  termination of this Plan (subject to Section
          6.1 below),  the bookkeeping  account of each Eligible  Director shall
          automatically be credited with 350 Deferred Stock Units.

     5.4  One-Time Grant. The bookkeeping  account of each Eligible  Director as
          of  December  1, 1997,  shall  automatically  be  credited  with 1,000
          Deferred  Stock  Units.  The  bookkeeping  account  of  each  Eligible
          Director first




Page 26
                                                             Exhibit 10(iii)A(6)

          elected to the Board  (whether by action of the Board of  Directors or
          the shareholders of the Corporation) after December 1, 1997, and prior
          to the  termination of this Plan (subject to Section 6.1 hereof) shall
          automatically  be credited with 1,000  Deferred  Stock Units as of the
          effective date of such election.

                                       4.

     Except as provided herein,  the provisions of the Plan shall remain in full
     force and effect.

     IN WITNESS  WHEREOF,  the parties hereto have executed this Amendment No. 1
as of the day and year first written above.

ATTEST:                                      NATIONAL SERVICE INDUSTRIES, INC.





By: /s/ Kenyon  W. Murphy                   By:  /s/ James S. Balloun