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National Service Industries, Inc.
As of July 14, 1997







                               As of July 14, 1997


National Service Industries, Inc.
NSI Center
1420 Peachtree Street, NE
Atlanta, GA 30309

Gentlemen:

     Reference  is hereby  made to the  Asset  Purchase  Agreement  by and among
National  Service  Industries,  Inc., a Delaware  corporation,  National Service
Industries,  Inc., a Georgia  corporation,  NSI Enterprises,  Inc., a California
corporation and G&K Services,  Inc., dated as of May 30, 1997 (the "Agreement").
Capitalized terms used in this letter without definition shall have the meanings
set forth in the Agreement. The parties hereby agree as follows:

     1. Reduction of Base Price.  Section 3.1 of the Agreement is hereby amended
to  provide  that  the  Base  Price  shall  be  reduced  from   $263,500,000  to
$262,850,000.

     2. Certain Obsolete Inventory.  New Inventory in excess of a six (6) months
supply,  as measured by the Business'  usage history,  may be shipped out of any
Acquired  Facility  by  Seller  on or  prior  to the  Closing  Date to a  Seller
distribution center, provided that such New Inventory quantities will not exceed
the  quantities  identified  in Schedule  4.23(c) as obsolete.  Purchaser or its
assignee  shall  have all rights  until  August 15,  1997 to  purchase  such New
Inventory as are contemplated by Section 3.4 of the Agreement.  Seller will keep
a written  record of such obsolete New Inventory and make such record  available
to Purchaser for review.

     3. Consent for Lakeland Branch #4710. Seller shall have until July 31, 1997
to obtain the consent of the  landlord  with respect to  assignment  of the Real
Property  Lease  covering  the  Acquired  Facility  identified  on  Exhibit A as
Lakeland  Branch #4710 and that assignment of such Real Property Lease under the
Agreement is  conditioned  on receipt of such consent.  In the event Seller does
not obtain the  landlord's  consent  with  respect  to  assignment  of such Real
Property Lease by July 31, 1997, then unless  otherwise  agreed to in writing by
Purchaser in its sole discretion,  Seller shall be required to exercise promptly
its purchase  option with respect  thereto and  thereafter,  promptly assign its
 
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purchase rights to Purchaser or its designated assignee,  as required by Section
6.3(e) of the Agreement.

     4. Assignable Special Industrial Accounts.  Notwithstanding anything in the
Asset  Purchase  Agreement  to the  contrary,  all revenue  attributed  to those
Assignable Special  Industrial  Accounts or portions thereof to be subcontracted
to Seller  by  Purchaser  pursuant  to  Section  1.5(c)(ii)(2)  of the  Purchase
Agreement will be included as part of the Average Weekly Industrial Revenue. The
subcontract  agreement which Seller will enter into with Purchaser,  pursuant to
which Seller will provide service to such Assignable Special Industrial Accounts
or portions thereof, will be on substantially the same terms as are set forth in
the  Subcontract  Agreement  attached to the Purchase  Agreement as Exhibit "B",
except that the  respective  roles of Seller and Purchaser  will be reversed and
except  that  Purchaser  will  have the  right  to  terminate  such  subcontract
agreement  with respect to any such  Assignable  Special  Industrial  Account or
portion thereof upon thirty (30) days' prior written notice to Seller.

     5.  Clarification  of Section 7.2.  Section 7.2 of the  Agreement  shall be
clarified as follows:

     (a) Buyer shall not be required to hire any  Employee of the Business if as
a result of such hire Buyer would be in violation of law.

     (b) The words "salaried,  exempt employees of the Business" as set forth in
Section 7.2(c) shall not include any employee who is paid in whole or in part on
a commission  basis (with the  exception of the  following  employees:  regional
sales managers;  managers of the service centers located in Utica, NY, Syracuse,
NY, Elmira, NY, Oneonta,  NY, and Schenectady,  NY; and the distribution manager
and client relations manager of the service center located in Utica, NY).

     6. Wages,  Commissions and Bonuses. All wages, sales commission and bonuses
earned by an  Employee  of the  Business  prior to the  Closing  Date will be an
Excluded  Liability,  the sole  responsibility  of Seller,  and paid directly by
Seller.  In addition  any sales  commission  and  bonuses  relating to a Covered
Account  where service was installed by Seller prior to the Closing Date will be
an Excluded  Liability,  the sole responsibility of Seller, and paid directly by
Seller,  except  that  such  commissions  and  bonuses  payable  to route  sales
representatives  and route drivers shall be paid by Purchaser and  reimbursed by
Seller to Purchaser.

     7. Vacation  Days.  Any vacation days earned by an Employee of the Business
(not covered by a Collective  Bargaining Agreement) which have been carried over
by such Employee  from any prior period to such  Employee's  current  employment
period  (the  "CarryOver  Days")  shall  be  an  Excluded  Liability,  the  sole
responsibility of Seller,  not included in the Accrued Employee Credit, and paid
directly by Seller. All  earned/vested,  or accrued vacation days of an Employee
of the Business relating to such Employee's current employment period (excluding
any CarryOver Days) shall be included in the Accrued Employee Credit.

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     8. Vested Sick Pay. All vested sick pay for  Employees of the Business (not
covered by a Collective  Bargaining  Agreement) shall be an Excluded  Liability,
the sole  responsibility of Seller, not included in the Accrued Employee Credit,
and paid directly by Seller.

     9. No Hiring or Firing  Freeze.  Seller  confirms  that since May 30,  1997
Seller has not authorized a hiring or firing freeze with respect to Employees of
the Business.

     10. Non-Exclusive License. Section 1.3(b) of the Agreement shall be amended
to add the  following  sentence:  "For the one (1)  year  period  following  the
Closing Date,  Seller hereby grants Purchaser a non-exclusive  license and right
to operate the  Business  under the names used by Seller to operate the Business
as of the Closing  Date and to use the marks,  names,  logos or other  rights of
Seller or an Affiliate in a manner consistent with and to the extent such marks,
names,  logos or other  rights were used  within the last  twelve  months in the
Business conducted by the Acquired  Facilities  identified on Exhibit "A" to the
Agreement  as Portland  #133,  Utica #107,  Youngstown  #3910,  Fort Myers #196,
Houston #461, Austin #167 and Corpus Christi #424."

     11. Richmond Volume.  The definition of Covered Accounts shall also include
Richmond Volume which shall be defined as all of the industrial  volume which on
the Closing Date is delivered out of Seller's  facility  known as Richmond #268.
Section  3.3(d)(iv)  of the  Agreement  shall be  amended  to add the words "and
Richmond  Volume"  immediately  after the words  "Jacksonville  Volume"  in such
section.  The first  sentence of Section  4.16 shall be amended to add the words
"in  addition to the  Richmond  Volume"  immediately  after the words "as of the
Closing Date" in such sentence. 

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     Please indicate your acknowledgment and agreement with the foregoing in the
space provided below.

                                  Yours truly,

                                  G&K SERVICES, INC.


                                  s/ William Hope
                                  William Hope, President and
                                  Chief Executive Officer


Acknowledged and Agreed to:

NATIONAL SERVICE INDUSTRIES, INC.
  a Delaware corporation

By:   s/ Brock Hattox
Its:  E.V.P.


NATIONAL SERVICE INDUSTRIES, INC.
a Georgia corporation

By:   s/ Brock Hattox
Its:  E.V.P.


NSI ENTERPRISES, INC.
a California corporation

By:   s/ Brock Hattox
Its:  E.V.P.

138948-7
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