Page 50
Exhibit 10(iii)A(27)(a)


                                                   July 22, 1996


Mr. Don W. Hubble
2621 Winslow Drive
Atlanta, Georgia 30305

Dear Don:

     This letter will confirm our agreement with respect to your  termination of
employment with National Service Industries, Inc. ("NSI").

     1. Effective  Date.  Your  termination  of employment  will be effective on
October  18,  1996 (the  "Effective  Date").  Our  expectation  is that you will
continue to work until the Effective  Date,  unless I advise you  otherwise,  in
which  case you will be placed on a paid leave of  absence  until the  Effective
Date.

     2.  Severance  Pay.  NSI will pay you as  severance  pay an amount equal to
$50,000 per month plus  one-twelfth  of any increase in the amount of bonus paid
to you for fiscal  1996 over the bonus paid to you for fiscal  1995.  Payment of
your  severance  pay will be made in  semi-monthly  installments  commencing  on
November 10, 1996, for the greater of (a) nine months or (b) twelve months minus
one-half of any period  remaining  between the date you commence any employment,
consulting  work, or other  arrangement for which you receive  compensation  and
October 18, 1997.

     3.  Additional  Benefits.  If  you  elect  COBRA  coverage  following  your
termination  of  employment,  you will continue to pay the portion of the health
insurance  premium  cost which you  currently  pay to NSI,  and NSI will pay the
remaining amount of your monthly premiums for COBRA coverage (including coverage
for your wife) until the sooner of (a) your  qualification  under a medical plan
offered by your  employer,  or (b) October 18,  1997.  NSI will amend your Stock
Option Agreements in two respects:  (1) all employee stock options you presently
hold will vest on or before  September 18 1996;  and (2) the time for exercising
all vested stock options will be extended  until October 31, 1998.  NSI will add
an appendix to the  Supplemental  Retirement  Plan for  Executives of NSI on the
Effective  Date to add  additional  years of  credited  service to the  credited
service you have in the plan on the Effective  Date so that your total  credited
service will equal twenty years.

     4. Other Terms of Payment. You acknowledge that the foregoing severance pay
and  benefits  exceed  those  which  you  would  otherwise   receive  upon  your
termination  of  employment.  Your severance pay and benefits will be subject to
appropriate tax  withholdings and will satisfy all sums which might otherwise be
due you from NSI, including,  without limitation,  vacation pay and bonuses, but
excluding any payments due you under the Executive  Deferred  Compensation  Plan
for Senior Officers,  the Senior Management  Benefit Plan, the Executive Savings


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                                                         Exhibit 10(iii)A(27)(a)



Plan, NSI's Pension Plan C, the  Supplemental  Retirement Plan for Executives of
NSI  (effective as of January 1, 1994),  and NSI's 401(k) Plan,  which  payments
will be made in  accordance  with  the  terms  of such  plans.  You  will not be
eligible to participate in any employee benefit plans following your termination
on the Effective  Date,  except as provided  above and as provided for under the
Consolidated Omnibus Budget Reconciliation Act of 1985 ("COBRA"), as amended.

     5.  Conditions  to  Payment.  You  understand  that the  severance  pay and
benefits  provided for hereunder are  conditioned  upon (a) your not disparaging
NSI or any  officer,  director of employee of NSI in any material  respect;  (b)
your not  disclosing  to any person or using for your own  benefit,  directly or
indirectly,  any  trade  secrets  or  confidential  information  of NSI,  unless
directed to do so by court order;  (c) your not  soliciting,  either directly or
indirectly,  any current employees of NSI to terminate their employment with NSI
and become employed by you or any person or entity with whom you are associated;
(d) your  compliance  with the  provisions  of  paragraph  6 below,  and (e) the
approval of the  Executive  Resource  and  Nominating  Committee of the Board of
Directors of NSI.

     6. Release.  In consideration of enhanced  severance pay and benefits,  and
subject to the  fulfillment  of the  condition  provided  in  subparagraph  5(e)
hereof, as described above, you hereby release and forever discharge NSI and its
divisions,  subsidiaries,  and  affiliates  and their  respective  shareholders,
officers,  directors,  employees,  agents or others acting on their behalf,  and
each of them, from any and all claims,  losses or expenses (including attorneys'
fees)  which you now have or have had or may  later  claim to have had as of the
date  hereof  against  them  arising  out of  your  employment  with  NSI or the
termination  of your  employment.  You  understand and agree that as a result of
this release and discharge, you will not, for example, be entitled to pursue any
claims  arising out of any alleged  violation of your rights  while  employed by
NSI,  including,  but not limited to, (a) claims for back pay,  reinstatement or
recovery of any losses or  compensatory,  punitive,  or other  damages to you or
your property resulting from any alleged violation of state or federal law, such
as (but not limited to),  claims arising under Title VII of the Civil Rights Act
of 1964, 42 U.S.C.  SS621, et. seq.  (prohibiting  discrimination  on account of
age); the Americans with Disabilities Act of 1990, 42 U.S.C.  SS12101,  et. seq.
(prohibiting  discrimination  on account of disability);  the Family and Medical
Leave  Act of 1993  (relating  to leaves  of  absence  for  family  and  medical
reasons);  and  any  similar  federal  or  state  law  claim  relating  to  your
employment;  and (b) claims  resulting or arising from or in connection with any
alleged tortuous conduct or other wrongdoing by NSI.

     7.  Acceptance  Period.  You have a period of twenty-one (21) days from the
date hereof to consider  whether or not you will accept the terms and conditions
set forth herein. You are advised to consult with an attorney and anyone else of
your  choosing  to obtain  advice  and  information  concerning  such  terms and
conditions.  In order to receive  the  severance  pay and  benefits,  it will be
necessary for you to accept such terms and  conditions by signing both copies of
this letter  agreement and returning one (1) copy to me within  twenty-one  (21)
days from the date hereof.

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Exhibit 10(iii)A(27)(a)




     8.  Revocation  Period.  You  understand  that  for a  period  of up to and
including seven (7) days after the date you sign this letter agreement,  you may
revoke it entirely.  No rights or obligations  contained in this agreement shall
become  enforceable  before the end of this seven (7) day revocation  period. If
you decide to revoke this letter agreement,  you will deliver a signed notice of
revocation  to me on or  before  the end of this  seven  (7)  day  period.  Upon
delivery  of a timely  notice of  revocation,  this  letter  agreement  shall be
canceled and void,  and neither  party to this letter  agreement  shall have any
rights or obligations arising under it.

     9.  Nondisclosure  Covenant.  You  agree  to hold  this  agreement  and the
contents  hereof in strict  confidence  and not to disclose such contents to any
third party,  other than your family  members and financial and legal  advisors,
without the prior written approval of NSI.

     10. Nondisparagement by NSI. NSI agrees to take appropriate steps to ensure
that the officers of NSI will not disparage you.

     11.  Miscellaneous.  This letter agreement constitutes the entire agreement
of the parties and  supersedes  any prior  agreements,  whether oral or written,
between the parties,  including  any prior  employment  agreements.  This letter
agreement  shall be binding upon and inure to the benefit of the  successors and
assigns  of  NSI  and  your  heirs,   administrators,   executors  and  personal
representatives.  If any provision of this letter  agreement is determined to be
unenforceable by a court of appropriate  jurisdiction,  the remaining provisions
of this letter will continue in effect at the discretion of NSI.

     12. Statement of Understanding. YOU STATE THAT YOU HAVE CAREFULLY READ THIS
LETTER  AGREEMENT,  UNDERSTAND ITS MEANING AND INTENT,  AND VOLUNTARILY AGREE TO
ABIDE BY ITS TERMS. YOU FURTHER STATE THAT THE ONLY PROMISES MADE TO YOU TO SIGN
THIS LETTER AGREEMENT ARE SET FORTH HEREIN.

                                            Sincerely,

                                            /s/ James S. Balloun
                                            James S. Balloun


AGREED TO AND ACCEPTED THIS

____ DAY OF JULY, 1996


/s/ Don W. Hubble
Don W. Hubble