Page 17
                                                             Exhibit 10(iii)A(b)


                       NONQUALIFIED STOCK OPTION AGREEMENT




     THIS AGREEMENT, made as of the 3rd day of January, 1996 (the "Grant Date"),
between  National  Service  Industries,   Inc.,  a  Delaware   corporation  (the
"Company"), and James S. Balloun (the "Optionee").

     WHEREAS,  the Company has adopted the  National  Service  Industries,  Inc.
Long-Term  Incentive  Program  (the  "Program")  in order to provide  additional
incentive to certain officers and employees of the Company and its Subsidiaries;
and

     WHEREAS,  the Committee  responsible for  administration of the Program has
determined to grant an option to the Optionee as provided herein.

     NOW, THEREFORE, the parties hereto agree as follows:

     1. Grant of Option.

          1.1 The Company  hereby  grants to the  Optionee  the right and option
(the  "Option") to purchase  all or any part of an  aggregate  of 250,000  whole
Shares subject to, and in accordance with, the terms and conditions set forth in
this Agreement.
                 
          1.2 The Option is not intended to qualify as an Incentive Stock Option
within the meaning of Section 422 of the Code.

          1.3 This  Agreement  shall be construed in accordance  and  consistent
with, and subject to, the provisions of the Program (the provisions of which are
incorporated  herein by reference) and, except as otherwise  expressly set forth
herein,  the  capitalized  terms  used in this  Agreement  shall  have  the same
definitions as set forth in the Program.

     2. Purchase Price.

          The price at which the Optionee  shall be entitled to purchase  Shares
upon the exercise of the Option shall be $32.50 per Share.

     3. Duration of Option.

          The  Option  shall be  exercisable  to the  extent  and in the  manner
provided  herein  for a  period  of ten (10)  years  from the  Grant  Date  (the
"Exercise Term");  provided,  however, that the Option may be earlier terminated
as provided in Section 6 hereof.

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                                                             Exhibit 10(iii)A(b)



     4. Exercisability of Option.

          Unless otherwise provided in this Agreement or the Program, the Option
shall  entitle the  Optionee to  purchase,  in whole at any time or in part from
time to time,  85,000 Shares  covered by the Option on or after August 31, 1996,
an additional  85,000 Shares  covered by the Option on or after August 31, 1997,
and an  additional  80,000  Shares  covered by the Option on or after August 31,
1998, and each such right of purchase  shall be cumulative  and shall  continue,
unless sooner  exercised or terminated as herein  provided  during the remaining
period of the Exercise Term.

     5. Manner of Exercise and Payment.

          5.1  Subject to the terms and  conditions  of this  Agreement  and the
Program,  the Option  may be  exercised  by  delivery  of written  notice to the
Company at its  principal  executive  office.  Such notice  shall state that the
Optionee is electing to exercise  the Option and the number of Shares in respect
of which the  Option  is being  exercised  and shall be signed by the  person or
persons  exercising the Option.  If requested by the  Committee,  such person or
persons  shall (i) deliver this  Agreement  to the  Secretary of the Company who
shall endorse thereon a notation of such exercise and (ii) provide  satisfactory
proof as to the right of such person or persons to exercise the Option.

          5.2  The  notice  of  exercise  described  in  Section  5.1  shall  be
accompanied  by the full  purchase  price for the Shares in respect of which the
Option is being exercised,  in cash, by check, or by transferring  Shares to the
Company  having a Fair Market  Value on the day  preceding  the date of exercise
equal to the cash amount for which such Shares are substituted.

          5.3 Upon receipt of notice of exercise and full payment for the Shares
in respect of which the Option is being exercised, the Company shall, subject to
Section 17 of the  Program,  take such action as may be  necessary to effect the
transfer to the  Optionee of the number of Shares as to which such  exercise was
effective.

          5.4 The  Optionee  shall not be deemed to be the holder of, or to have
any of the rights of a holder with  respect to any Shares  subject to the Option
until (i) the Option  shall have been  exercised  pursuant  to the terms of this
Agreement  and the  Optionee  shall  have paid the full  purchase  price for the
number of Shares in respect of which the Option was exercised,  (ii) the Company
shall  have  issued and  delivered  the  Shares to the  Optionee,  and (iii) the
Optionee's  name shall have been entered as a stockholder of record on the books
of the  Company,  whereupon  the  Optionee  shall  have  full  voting  and other
ownership rights with respect to such Shares.


                                                                         Page 19
                                                             Exhibit 10(iii)A(b)



     6. Termination of Employment.

          6.1 Death, Disability,  or Change in Control. If the employment of the
Optionee is terminated as a result of his death,  Disability,  or within two (2)
years following a Change in Control, the Option shall continue to be exercisable
in whole or in part (to the  extent  exercisable  on the date of the  Optionee's
termination  of employment) at any time within three (3) years after the date of
such  termination  of  employment,  but in no event after the  expiration of the
Exercise  Term.  In the  event of the  Optionee's  death,  the  Option  shall be
exercisable,  to the extent provided in the Program and this  Agreement,  by the
legatee  or  legatees  under his will,  or by his  personal  representatives  or
distributees  and such person or persons shall be  substituted  for the Optionee
each time the Optionee is referred to herein.

          6.2  Retirement  at Age  Sixty-five  (65).  If the  employment  of the
Optionee  is  terminated  as a  result  of  Optionee's  Retirement  (on or after
Optionee's  sixth-fifth  (65th)  birthday),  the  Option  shall  continue  to be
exercisable  in whole or in part (to the extent  exercisable  on the date of the
Optionee's  termination  of  employment) at any time within five (5) years after
the date of such termination of employment, but in no event after the expiration
of the Exercise Term.

          6.3  Termination   Without  Cause.  In  the  event  of  the  Company's
termination of Optionee's  employment  without Cause, and other than as provided
in Sections 6.1 and 6.2 above,  the Option shall  become  immediately  and fully
exercisable.  "Cause" shall mean any act(s) on Optionee's part that  constitutes
fraud,  a felony  involving  dishonesty,  a breach of fiduciary  duty,  or gross
malfeasance or habitual neglect of Optionee's  duties for the Company;  provided
that (i) Optionee  has been given  written  notice of such actions  constituting
Cause at least  fifteen (15) days prior to any meeting of the Board of Directors
of the Company at which his  termination is to be considered;  (ii) Optionee has
been  given the  opportunity  to be heard by the  Board;  and  (iii)  Optionee's
termination for Cause is evidenced by a resolution  adopted by two-thirds of the
Board.

          6.4  Termination  of Option.  If the  employment  of the  Optionee  is
terminated  for any reason  other than the reasons set forth in Sections 6.1 and
6.2 (including the Optionee's ceasing to be employed by a Subsidiary or Division
as a result of the sale of such  Subsidiary  or  Division or an interest in such
Subsidiary  or  Division),  the  Option  shall  terminate  on  the  date  of the
Optionee's termination of employment, whether or not exercisable.

     7. Effect of Change in Control and Termination of Employment Without Cause

          Notwithstanding  anything contained in this Agreement to the contrary,
in the event of a Change in Control, (i) the Option shall become immediately and
fully  exercisable,  and (ii) the Optionee  will be  permitted to surrender  for
cancellation, within sixty (60) days after such Change in Control, the Option or

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                                                             Exhibit 10(iii)A(b)



any portion of the Option to the extent not yet exercised and the Optionee shall
be  entitled to receive  immediately  a cash  payment in an amount  equal to the
excess,  if any, of (A) the greater of (x) the Fair  Market  Value,  on the date
preceding  the date of the  surrender,  of the  Shares  subject to the Option or
portion of the Option  surrendered  or (y) the Adjusted Fair Market Value of the
Shares subject to the Option or the portion of the Option surrendered,  over (B)
the  aggregate  purchase  price  for such  Shares  under the  Option;  provided,
however,  that if the Option  was  granted  within  six (6) months  prior to the
Change in Control and the  Optionee may be subject to  liability  under  Section
16(b) of the  Exchange  Act, the  Optionee  shall be entitled to  surrender  for
cancellation  the Option or any portion of the Option  during the sixty (60) day
period  following  the  expiration  of six (6) months from the Grant Date and to
receive  the  amount   described  above  with  respect  to  such  surrender  for
cancellation.

     8. Nontransferability.

          The Option shall not be transferable other than-by will or by the laws
of descent and distribution.  Notwithstanding  the foregoing,  the Option may be
transferred,  in whole or in part, without consideration,  by written instrument
signed by the  Optionee,  to any  members of the  immediate  family of  Optionee
(i.e., spouse,  children and grandchildren),  any trusts for the benefit of such
family members or any  partnerships  whose only partners are such family members
(the "Permitted Transferees").  Appropriate evidence of any such transfer to the
Permitted  Transferees  shall  be  delivered  to the  Company  at its  principal
executive  office.  During the  lifetime of the  Optionee,  the Option  shall be
exercisable  only  by  the  Optionee,  or,  if  applicable,   by  the  Permitted
Transferees.

     9. No Right to Continued Employment.

          Nothing in this  Agreement  or the  Program  shall be  interpreted  or
construed to confer upon the Optionee any right with respect to  continuance  of
employment by the Company,  nor shall this Agreement or the Program interfere in
any way with the right of the Company to terminate the Optionee's  employment at
any time.

     10. Adjustments.

          In the event of a Change in  Capitalization,  the  Committee  may make
appropriate  adjustments  to the  number  and class of Shares or other  stock or
securities subject to the Option and the purchase price for such Shares or other
stock or securities. The Committee's adjustment shall be made in accordance with
the  provisions  of Section 11 of the Program and shall be effective  and final,
binding, and conclusive for all purposes of the Program and this Agreement.

                                                                         Page 21
                                                             Exhibit 10(iii)A(b)



     11. Terminating Events.

          Subject  to  Section  7  hereof,  upon the  effective  date of (i) the
liquidation or dissolution of the Company or (ii) a merger or  consolidation  of
the Company (a "Transaction"), the Option shall continue in effect in accordance
with its terms and the  Optionee  shall be entitled to receive in respect of all
Shares subject to the Option,  upon exercise of the Option,  the same number and
kind of stock,  securities,  cash,  property,  or other  consideration that each
holder of Shares was entitled to receive in the Transaction.

     12. Withholding of Taxes.

          12.1 The Company shall have the right to deduct from any  distribution
of cash to the Optionee an amount equal to the federal,  state, and local income
taxes  and  other  amounts  as  may be  required  by  law  to be  withheld  (the
"Withholding  Taxes") with respect to the Option. If the Optionee is entitled to
receive  Shares  upon  exercise  of the  Option,  the  Optionee  shall  pay  the
Withholding  Taxes to the Company in cash prior to the  issuance of such Shares.
In  satisfaction  of the  Withholding  Taxes,  the  Optionee  may make a written
election  (the  "Tax  Election"),  which  may be  accepted  or  rejected  in the
discretion of the Committee,  to have withheld a portion of the Shares  issuable
to him or her upon exercise of the Option, having an aggregate Fair Market Value
on the date preceding the Tax Date (as defined  below) equal to the  Withholding
Taxes,  provided  that (i) if the  Optionee  may be subject to  liability  under
Section 16(b) of the Exchange Act (unless his or her  employment  was terminated
due to  Disability or death),  (A) the Optionee  makes the Tax Election at least
six (6) months  after the Grant Date and (B) the Tax  Election is made either at
least six (6) months prior to the date that the amount of the Withholding  Taxes
are determined  (the "Tax Date") or during the ten (10) day period  beginning on
the third  business  day and ending on the twelfth  business day  following  the
release for  publication  of the  Company's  quarterly or annual  statements  of
earnings, (ii) the Tax Election is made prior to the Tax Date, and (iii) the Tax
Election  is  irrevocable;  provided,  however,  in the event  that the Tax Date
occurs subsequent to the exercise of the Option,  the Optionee shall tender back
to the Company on the Tax Date that number of Shares  having a Fair Market Value
on the date preceding the Tax Date equal to the Withholding Taxes.

     13. Employee Bound by the Program.

          The Optionee hereby acknowledges  receipt of a copy of the Program and
agrees to be bound by all the terms and provisions thereof.

     14. Modification of Agreement.

          This Agreement may be modified, amended, suspended, or terminated, and
any terms or conditions may be waived, but only by a written instrument executed
by the parties hereto.

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                                                             Exhibit 10(iii)A(b)



     15. Severability.

          Should any provision of this Agreement be held by a court of competent
jurisdiction  to be  unenforceable  or invalid  for any  reason,  the  remaining
provisions  of this  Agreement  shall not be affected by such  holding and shall
continue it full force in accordance with their terms.

     16. Governing Law.

          The validity,  interpretation,  construction,  and performance of this
Agreement shall be governed by the laws of the State of Delaware  without giving
effect to the conflicts of laws principles thereof.

     17. Successors in Interest.

          This Agreement  shall inure to the benefit of and be binding upon each
successor  to the  Company.  This  Agreement  shall  inure to the benefit of the
Optionee's  legal  representatives  and Permitted  Transferees.  All obligations
imposed  upon the  Optionee  and all rights  granted to the  Company  under this
Agreement shall be final,  binding,  and conclusive  upon the Optionee's  heirs,
executors, administrators, successors, and Permitted Transferees.

     18. Resolution of Disputes.

          Any dispute or disagreement  which may arise under, or as a result of,
or in any way relate to, the  interpretation,  construction,  or  application of
this Agreement  shall be determined by the  Committee.  Any  determination  made
hereunder  shall be final,  binding,  and  conclusive  on the  Optionee  and the
Company for all purposes.


ATTEST:                             NATIONAL SERVICE INDUSTRIES, INC.



/s/ Carol Ellis Morgan              By: /s/ John G. Medlin, Jr
    Assistant Secretary                     John G. Medlin, Jr.
                                            Chairman, Executive Resource,
                                            Compensation and Nominating
                                            Committee of The Board of Directors
                                                  
     
                                            /s/ James S. Balloun
                                            Name of Optionee:  James S. Balloun