<PAGE>
                          QUARTERLY REPORT ON FORM 10-Q
                     U.S. SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON D.C. 20549
                            _________________________
                                        
(Mark One)
[ X ] QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE  ACT
      OF 1934
      For the quarterly period ended March 28, 1999

                                       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: 1-12432


                      AMERICAN POWER CONVERSION CORPORATION
             (Exact name of Registrant as specified in its charter)
                                        
                                        
                 MASSACHUSETTS                     04-2722013
     (State or other jurisdiction of    (I.R.S. employer identification no.)
     incorporation or organization)               
                                        
                                        
             132 FAIRGROUNDS ROAD, WEST KINGSTON, RHODE ISLAND 02892
                                  401-789-5735
          (Address and telephone number of principal executive offices)


Indicate  by check mark whether the Registrant (1) has filed all reports  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  [   ]

                                        

     Registrant's Common Stock outstanding, $.01 par value, at May 6, 1999 -
                                95,957,000 shares

                                        1
<PAGE>
                                                                       FORM 10-Q
                                                                  March 28, 1999


             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
                                        
                                      INDEX

 
                                                                   Page No.

Part I - Financial Information:
     
  Item 1.  Consolidated Condensed Financial Statements:
           Consolidated Condensed Balance Sheets -
           March 28, 1999 (Unaudited) and December 31, 1998         3 - 4
           
           Consolidated Condensed Statements of Income -
           Three Months Ended
           March 28, 1999 and March 29, 1998 (Unaudited)              5
           
           Consolidated Condensed Statements of Cash Flows -
           Three Months Ended
           March 28, 1999 and March 29, 1998 (Unaudited)              6
           
           Notes to Consolidated Condensed Financial Statements
           (Unaudited)                                              7 - 8
           
  Item 2.  Management's Discussion and Analysis of Financial
           Condition and Results of Operations                      8 - 14
           
  Item 3.  Quantitative and Qualitative Disclosures About 
           Market Risk                                                14
           
Part II - Other Information:

  Item 1.  Legal Proceedings                                          14
     
  Item 6.  Exhibits and Reports on Form 8-K                           14
     
Signatures                                                            15

                                        2
<PAGE>
                                                                       FORM 10-Q
                                                                  March 28, 1999
PART I - CONSOLIDATED CONDENSED FINANCIAL STATEMENTS

ITEM 1 - FINANCIAL STATEMENTS
<TABLE>

             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
                      CONSOLIDATED CONDENSED BALANCE SHEETS
                                 (In thousands)
                                        
                                     ASSETS
<CAPTION>
                                        
                                        
                                                            March 28,        December 31,
                                                                1999                1998
                                                                     (Unaudited)               
<S>                                                          <C>                 <C>
                                        
Current assets:                                                                  
Cash and cash equivalents                                   $225,986            $219,908
Accounts receivable,                                                             
 less allowance for doubtful accounts of                                         
 $17,544 in 1999 and $15,471 in 1998                         197,423             180,356
Inventories:                                                                     
 Raw materials                                               105,167              87,975
 Work-in-process and finished goods                          138,355             140,707
Total inventories                                            243,522             228,682
                                                                                 
Prepaid expenses and other current assets                     18,336              17,801
                                                                                 
Deferred income taxes                                         25,776              28,498
                                                                                 
Total current assets                                         711,043             675,245
                                                                                 
Property, plant, and equipment:                                                  
 Land, buildings and improvements                             52,384              51,735
 Machinery and equipment                                     125,663             125,274
 Office equipment, furniture, and fixtures                    47,745              44,955
 Purchased software                                           12,001              11,505
                                                                                 
                                                             237,793             233,469
                                                                                 
Less accumulated depreciation and amortization                90,149              85,205
                                                                                 
Net property, plant, and equipment                           147,644             148,264
                                                                                 
Goodwill and other intangibles                                51,490              45,837
                                                                                 
Other assets                                                   2,308               2,637
                                                                                 
                                                                                 
Total assets                                                $912,485            $871,983
                                        
</TABLE>
                                        
     See accompanying notes to consolidated condensed financial statements.

                                        3
<PAGE> 
                                                                       FORM 10-Q
                                                                  March 28, 1999

<TABLE>

             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
                CONSOLIDATED CONDENSED BALANCE SHEETS (CONTINUED)
                                 (In thousands)
                                        
                      LIABILITIES AND SHAREHOLDERS' EQUITY
<CAPTION>
                                        
                                        
                                                            March 28,        December 31,
                                                                1999                1999
                                                                     (Unaudited)               
<S>                                                          <C>                 <C>
Current liabilities:                                                             
Short term debt                                              $ 8,805             $12,540
Accounts payable                                              75,449              75,190
Accrued expenses                                              37,257              28,560
Accrued compensation                                          23,722              22,130
Accrued sales and marketing programs                          16,488              17,824
Accrued retirement contributions                               3,893               2,469
Income taxes payable                                          23,844              22,753
                                                                                 
Total current liabilities                                    189,458             181,466
                                                                                 
Deferred tax liability                                         5,703               7,500
                                                                                 
Total liabilities                                            195,161             188,966
                                                                                 
Minority interest                                                  -               1,725
                                                                                 
Shareholders' equity:                                                            
Common stock, $.01 par value;                                                    
 authorized 200,000 shares; issued 96,040                                        
 shares in 1999 and 95,973 shares in 1998                        960                 960
Additional paid-in capital                                    68,247              67,080
Retained earnings                                            649,092             614,301
Treasury stock, 125 shares, at cost                           (1,551)             (1,551)
Accumulated other comprehensive income                           576                 502
                                                                                 
Total shareholders' equity                                   717,324             681,292
                                                                                 
Total liabilities and shareholders' equity                  $912,485            $871,983
                                        
                                        
</TABLE>
                                        
     See accompanying notes to consolidated condensed financial statements.

                                        4
<PAGE>    
                                                                       FORM 10-Q
                                                                  March 28, 1999

<TABLE>

             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
                   CONSOLIDATED CONDENSED STATEMENTS OF INCOME
                    (In thousands except earnings per share)
<CAPTION>
                                        
                                        
                                                                 Three months ended
                                                           March 28,           March 29,
                                                               1999                1998
                                                                     (Unaudited)
                                                                                 
<S>                                                        <C>                 <C>
Net sales                                                  $277,185            $218,867
                                                                                 
Cost of goods sold                                          155,030             120,855
                                                                                 
Gross profit                                                122,155              98,012
                                                                                 
Operating expenses:                                                              
Marketing, selling, general and administrative               66,324              55,367
Research and development                                      8,952               7,724
                                                                                 
Total operating expenses                                     75,276              63,091
                                                                                 
Operating income                                             46,879              34,921
                                                                                 
Other income, net                                             2,471               3,534
                                                                                 
Earnings before income taxes                                 49,350              38,455
                                                                                 
Income taxes                                                 14,559              11,729
                                                                                 
Net income                                                  $34,791             $26,726
                                                                                 
Basic earnings per share                                    $   .36              $  .28
                                                                                 
Basic weighted average shares outstanding                    95,880              95,304
                                                                                 
Diluted earnings per share                                  $   .36              $  .28
                                                                                 
Diluted weighted average shares outstanding                  97,788              96,568
                                        
</TABLE>
                                        
     See accompanying notes to consolidated condensed financial statements.

                                        5
<PAGE>
                                                                       FORM 10-Q
                                                                  March 28, 1999

<TABLE>

             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
                 CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                                 (In thousands)
                                        
<CAPTION>
                                        
                                        
                                                                    Three months ended
                                                           March 28,            March 29,
                                                               1999                 1998
                                                                          (Unaudited)
<S>                                                         <C>                  <C>
Cash flows from operating activities                                             
Net income                                                  $34,791              $26,726
Adjustments to reconcile net income to net                                       
 cash provided by operating activities:                                           
Depreciation and amortization                                 5,805               6,396
Provision for doubtful accounts                               2,314               1,248
Deferred income taxes                                           925              (4,891)
Changes in operating assets and liabilities:                                     
 Accounts receivable                                         (19,381)             (20,403)
 Inventories                                                 (14,840)             (26,723)
 Prepaid expenses and other current assets                     (535)              (2,066)
 Other assets                                                    329                  31
 Accounts payable                                                259              29,673
 Accrued expenses                                             10,377                 160
 Income taxes payable                                          1,091              16,571
Net cash provided by operating activities                    21,135              26,722
                                                                                 
Cash flows from investing activities                                             
Capital expenditures, net of capital grants                 (4,324)              (9,716)
Acquisition of minority interest                            (8,165)                   -
Net cash used in investing activities                       (12,489)             (9,716)
                                                                                 
Cash flows from financing activities                                             
Repayment of short term debt                                (3,735)                   -
Proceeds from issuances of common stock                       1,167                 746
Net cash (used in) provided by financing activities         (2,568)                 746
                                                                                 
Net change in cash and cash equivalents                       6,078              17,752
Cash and cash equivalents at beginning of period            219,908              270,134
Cash and cash equivalents at end of period                  $225,986             $287,886
                                        
Supplemental cash flow disclosures                                               
Cash paid for income taxes (net of refunds)                 $11,323              $    -
                                        
                                       
</TABLE>
                                        
     See accompanying notes to consolidated condensed financial statements.

                                        6
<PAGE>
                                                                       FORM 10-Q
                                                                  March 28, 1999



             AMERICAN POWER CONVERSION CORPORATION AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                   (Unaudited)



1.   Management Representation

In  the  opinion  of  management, the accompanying unaudited  interim  financial
statements  contain  all  adjustments  (consisting  of  only  normal   recurring
accruals) necessary to present fairly the financial position and the results  of
operations  for the interim periods.  The results of operations for the  interim
periods  are not necessarily indicative of results to be expected for  the  full
year.

2.   Principles of Consolidation

The  consolidated  financial  statements include  the  financial  statements  of
American  Power  Conversion Corporation and its wholly-owned subsidiaries.   All
intercompany accounts and transactions are eliminated in consolidation.

3.   Per Share Data

Basic  earnings  per share is computed by dividing net income  by  the  weighted
average number of common shares outstanding during the period.  Diluted earnings
per  share is computed by dividing net income by the weighted average number  of
common  shares  and  dilutive  potential common shares  outstanding  during  the
period.  Under the treasury stock method, the unexercised options are assumed to
be  exercised  at  the beginning of the period or at issuance,  if  later.   The
assumed  proceeds are then used to purchase common shares at the average  market
price during the period.

<TABLE>
<CAPTION>
 In thousands                                            Three months ended
                                                  March 28,            March 29,
                                                      1999                 1998
<S>                                               <C>                  <C>
 Basic weighted average shares outstanding          95,880                95,304
 Net effect of dilutive potential common shares                                            
 outstanding based on the treasury stock                                                   
 method using the average market price               1,908                 1,264
 Diluted weighted average shares outstanding        97,788                96,568

</TABLE>

Potential  common shares for which inclusion would have the effect of increasing
diluted   earnings  per  share  (i.e.,  antidilutive)  are  excluded  from   the
computation.  Antidilutive potential common shares outstanding at March 28, 1999
and March 29, 1998 were approximately 163,000 and 157,000, respectively.

4.   Shareholders' Equity

Changes in paid-in capital for the periods presented represent the issuances  of
common stock resulting from the exercise of employee stock options.

                                        7
<PAGE>


5.   Comprehensive Income

The components of comprehensive income, net of tax, are as follows:

 In thousands                                          Three months ended
                                               March 28,            March 29,
                                                   1999                 1998
                                                                              
 Net income                                     $34,791              $26,726
                                                                        
 Other comprehensive income, net of tax:                                
 Change in foreign currency translation adjustment   74                   -
  Other comprehensive income                         74                   -
                                                                        
 Comprehensive income                           $34,865              $26,726

6.   Operating Segment Information

Basis for presentation
The  Company's  operating  businesses  design,  manufacture,  and  market  power
protection  equipment  and  related software and accessories  for  computer  and
computer-related  equipment.  The Company manages its businesses  based  on  the
nature   of   products  provided.   These  businesses  share  similar   economic
characteristics and have been aggregated into one reportable operating  segment.
The  Company  evaluates  the  performance of  its  businesses  based  on  direct
contribution   margin.   Direct  contribution  margin  includes   research   and
development   ("R&D"),   marketing,   and   administrative   expenses   directly
attributable  to  the segment and excludes certain expenses  which  are  managed
outside the reportable segment.  Costs excluded from segment profit are indirect
operating expenses, primarily consisting of selling and corporate expenses,  and
income  taxes.  Expenditures for additions to long-lived assets are not reported
to management by the operating businesses.

Summary operating segment information is as follows:

 In thousands                                                 Three months ended
                                              March 28,            March 29,
                                                  1999                 1998
                                                                           
 Net sales                                    $277,185               $218,867
                                                                            
 Segment direct contribution margin           $109,657                $84,747
 Indirect operating expenses                    62,778                 49,826
 Other income, net                               2,471                  3,534
Earnings before incomes taxes                  $49,350                $38,455


ITEM 2.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
          CONDITION AND RESULTS OF OPERATIONS

RESULTS OF OPERATIONS:

Revenues

Net  sales  were  $277.2 million for the first quarter of 1999, an  increase  of
26.6% compared to $218.9 million for the same period in 1998.  The increase  was
attributable to continued strong demand for the Company's uninterruptible  power
supply (UPS) and surge protection products, combined with $20.4 million in first

                                       8
<PAGE>
quarter  1999  sales  attributable to Silcon A/S ("Silcon")  (see  "Acquisition"
below).   First quarter net sales growth was strong worldwide with the  Americas
(North  and  Latin America) growing 14%, EMEA (Europe, Middle East  and  Africa)
growing  46%, and the Asia Pacific region growing 57%.  International net  sales
(excluding  Canada)  comprised  42% and 35% of total  net  sales  in  the  first
quarters of 1999 and 1998, respectively.

Cost of Goods Sold

Cost of goods sold was $155.0 million or 55.9% of net sales in the first quarter
of 1999 compared to $120.9 million or 55.2% in the first quarter of 1998.  First
quarter  1999  gross margin was 44.1% of sales, approximately  70  basis  points
lower than the comparable period in 1998.  Substantially all of the gross margin
decrease was related to product mix as the Company's high-power UPS business now
accounts for a larger percentage of revenue.  Total inventory reserves at  March
28, 1999 were $14.4 million compared to $13.3 million at December 31, 1998.  The
Company's  reserve estimate methodology involves quantifying the total inventory
position  having  potential  loss  exposure, reduced  by  an  amount  reasonably
forecasted to be sold, and adjusting its interim reserve provisioning  to  cover
the net loss exposure.

Operating Expenses

Operating  expenses  include  marketing,  selling,  general  and  administrative
(SG&A), and research and development (R&D) expenses.

SG&A expenses were $66.3 million or 23.9 % of net sales for the first quarter of
1999  compared to $55.4 million or 25.3 % of net sales for the first quarter  of
1998.   The increase in total spending over last year was due primarily to costs
associated   with  increased  staffing  and  operating  expenses   of   selling,
administrative,  and marketing functions, as well as increased  advertising  and
promotional  costs.  However, the decrease as a percentage of sales  from  first
quarter  1998  to  first  quarter 1999 is attributable  to  certain  fixed  SG&A
expenses  spread  over a higher revenue base, as well as the  Company's  focused
efforts  to manage spending.  The allowance for doubtful accounts at  March  28,
1999  was  8.2% of accounts receivable, compared to 7.9% at December  31,  1998.
The  Company  continues  to experience strong collection performance.   Accounts
receivable  balances  outstanding  over  60  days  represented  6.6%  of   total
receivables at March 28, 1999, down from 8.6% at December 31, 1998.   Write-offs
of  uncollectible accounts have historically represented less than 1%  of  total
receivable balances.  A majority of international customer balances are  covered
by receivables insurance.

R&D expenses were $9.0 million or 3.2% of net sales and $7.7 million or 3.5%  of
net  sales for the first quarters of 1999 and 1998, respectively.  The  increase
in  total  R&D  spending primarily reflects increased numbers  of  software  and
hardware  engineers  and  costs  associated with  new  product  development  and
engineering support.

Other Income, Net and Income Taxes

Other  income  during  the  first quarter of 1999 was comprised  principally  of
interest income, which decreased from the comparable period in 1998 due to lower
average cash balances available for investment during 1999, due largely to  cash
used in the acquisition of Silcon (see "Acquisition" below).

The  Company's effective income tax rates were approximately 29.5% and 30.5% for
the  quarters  ended  March  28, 1999 and March  29,  1998,  respectively.   The
decrease  from  last year is due to the expected tax savings from an  increasing
portion  of  taxable earnings being generated from the Company's  operations  in
Ireland,  a  jurisdiction  which currently has  a  lower  income  tax  rate  for
manufacturing companies than the present U.S. statutory income tax rate.

LIQUIDITY AND CAPITAL RESOURCES

Working  capital at March 28, 1999 was $521.6 million compared to $493.8 million
at December 31, 1998.  The Company has been able to increase its working capital
position  as  the  result  of  continued strong operating  results  and  despite
internally  financing the capital investment required to expand its  operations.
The  Company's cash position increased to $226.0 million at March 28, 1999  from
$219.9 million at December 31, 1998.

                                        9
<PAGE>

Worldwide  inventories were $243.5 million at March 28, 1999 compared to  $228.7
million  at  December 31, 1998.  Inventory levels as a percentage  of  quarterly
sales were 88% in the first quarter of 1999 up from 72% in the fourth quarter of
1998.   The  first  quarter  1999  inventory  build  was  primarily  related  to
anticipation  of increased demand patterns during the second half  of  the  year
which result from typical seasonal factors.

At  March  28, 1999, the Company had $50 million available for future borrowings
under an unsecured line of credit agreement at a floating interest rate equal to
the bank's cost of funds rate plus .625% and an additional $15 million under  an
unsecured  line  of  credit agreement with a second bank at a  similar  interest
rate.   No borrowings were outstanding under these facilities at March 28, 1999.
In  connection with the 1998 acquisition of a majority interest in  Silcon  (see
"Acquisition"  below), the Company acquired $24.8 million in  bank  indebtedness
with interest rates ranging from 4% to 8%.  The Company repaid $12.3 million  of
this  indebtedness  during the second half of 1998 and $3.7 million  during  the
first  quarter  of 1999.  The Company had no significant financial  commitments,
other than those required in the normal course of business, at March 28, 1999.

Capital  investment  for  the  first quarter  of  1999  consisted  primarily  of
manufacturing  and office equipment, buildings and improvements,  and  purchased
software  applications.  The nature and level of capital spending  was  made  to
improve  manufacturing capabilities, principally in the U.S. and the  Far  East,
and  to  support  the  increased marketing, selling, and administrative  efforts
necessitated  by the Company's growth.  Net capital expenditures  were  financed
from available operating cash.  The Company had no material capital commitments,
other than those required in the normal course of business at March 28, 1999.

The  Company has agreements with the Industrial Development Authority of Ireland
("IDA")  under  which the Company receives grant monies for costs  incurred  for
machinery,  equipment, and building improvements for its  Galway  and  Castlebar
facilities equal to 40% and 60%, respectively, of such costs up to a maximum  of
$13.1 million and $1.3 million, respectively.  Such grant monies are subject  to
the  Company  meeting  certain employment goals and  maintaining  operations  in
Ireland  until  termination of the respective agreements.  The total  cumulative
amounts  of capital grant claims submitted and received through March  28,  1999
for  the  Galway  facility were approximately $12.3 million  and  $8.8  million,
respectively.   The  total cumulative amount of capital grant  claims  submitted
through  March 28, 1999 for the Castlebar facility was $1.2 million; no  capital
grant  claims  had  been  received for the Castlebar facility.   Under  separate
agreements  with the IDA, the Company receives direct reimbursement of  training
costs  at  its  Galway  and Castlebar facilities for up to $3,000  and  $12,500,
respectively, per new employee hired.  The total cumulative amounts of  training
grant  claims  submitted  and received through March 28,  1999  for  the  Galway
facility  were  approximately $1.2 million and $1.2 million, respectively.   The
total  cumulative  amount of training grant claims submitted through  March  28,
1999  for  the  Castlebar facility was approximately $1.0 million;  no  training
grant claims had been received for the Castlebar facility.

During  the  fourth  quarter  of 1998, the Company established  a  manufacturing
operation  in  India.  The Company is leasing a 42,000 square foot  facility  in
Bangalore and expects to begin manufacturing selected products at this  facility
during the second quarter of 1999.  Capital expenditures for the India expansion
are being financed from operating cash.

During  the  first  quarter  of  1998, the Company established  a  manufacturing
operation  in  China.  The Company is leasing a 50,000 square foot  facility  in
Suzhou  and  began manufacturing selected products at this facility  during  the
third  quarter  of  1998.   Capital expenditures for the  China  expansion  were
financed from operating cash.

The  Company's manufacturing operation in the Philippines is operating within  a
designated  economic zone which provides certain economic incentives,  primarily
in  the  form of tax exemptions.  In August 1998, the Company purchased a  third
manufacturing  facility in the Philippines for approximately $750,000,  financed
from operating cash.

                                       10
<PAGE>
The   Company  continues  to  evaluate  international  manufacturing  expansion,
including additional locations in the Far East and South America.

Management  believes  that current internal cash flows together  with  available
cash,  available credit facilities or, if needed, the proceeds from the sale  of
additional  equity, will be sufficient to support anticipated  capital  spending
and other working capital requirements for the foreseeable future.

Acquisition of Silcon A/S

Early  in  the  second quarter of 1998, the Company entered  into  a  definitive
agreement with the principal management shareholders of Silcon to acquire  stock
of Silcon, a Denmark-based manufacturer of three-phase UPSs up to 480 kilo volt-
amps  ("kVA"), and the Company commenced a tender offer for Silcon  shares.   In
June  1998,  the  initial  tender offer and purchase  of  stock  from  principal
management shareholders was completed enabling the Company to operate Silcon  as
a  majority-owned  subsidiary.  During the second  half  of  1998,  the  Company
increased  its  ownership  percentage to 89%.   In  January  1999,  the  Company
attained ownership of more than 90% of the share capital of Silcon through  open
market  purchases  financed  from  operating  cash  and  commenced  a  mandatory
redemption  of  the  remaining  Silcon shares.   Through  this  mandatory  share
redemption, the Company anticipates that it will complete its acquisition of the
remaining  outstanding  shares of Silcon during the second  half  of  1999.   In
connection with the mandatory redemption, the Copenhagen Stock Exchange approved
the  de-listing of Silcon's shares effective March 1, 1999.  The Company's  cash
outlays  associated with the acquisition of $64.4 million during 1998  and  $8.2
million during the first quarter of 1999 were financed from operating cash.

The purchase price was allocated to the net tangible and identifiable intangible
assets  acquired and to acquired in-process R&D ("acquired R&D").  Acquired  R&D
includes  the value of products in the development stage that are not considered
to  have  reached technological feasibility and that have no alternative  future
uses.   In accordance with applicable accounting rules, acquired R&D is required
to  be expensed.  Accordingly, $7.6 million of the acquisition cost was expensed
in  1998.   The remaining purchase price exceeded the fair value of the tangible
net  assets  acquired by approximately $54 million, consisting  of  identifiable
intangible  assets  and goodwill, which is being amortized  on  a  straight-line
basis over 15 years.  The acquisition has been accounted for as a purchase  and,
accordingly,  Silcon's  results  of operations are  included  in  the  Company's
consolidated financial statements from the date of acquisition.

Foreign Currency Activity

The  Company invoices its customers in Denmark, France, Germany, Great  Britain,
Switzerland,  and  Japan  in their respective local  currencies.   Realized  and
unrealized transaction gains or losses are included in the results of operations
and  are  measured  based upon the effect of changes in exchange  rates  on  the
actual or expected amount of functional currency cash flows.  Transaction  gains
and  losses were not material to the results of operations in the first quarters
of 1999 and 1998.

At  March  28, 1999 the Company's unhedged foreign currency accounts receivable,
by currency, were as follows:

 In thousands                 Foreign Currency           US Dollars
 German Marks                            19,596               $10,887
 British Pounds                           5,393                 8,812
 French Francs                           40,579                 6,729
 Swiss Francs                             7,458                 5,108
 Danish Kroner                            3,322                   486
 Japanese Yen                         1,693,536                14,352

The  Company  also  had  non-trade  receivables  of  4.2  million  Irish  Pounds
(approximately  US$5.8 million), as well as Irish Pound denominated  liabilities
of  3.3 million (approximately US$4.7 million).  The Company also had short term
debt  and  liabilities  denominated in various European  currencies  of  US$38.5
million, as well as Yen denominated liabilities of approximately US$.9 million.

                                       11
<PAGE>

The  Company  continually reviews its foreign exchange  exposure  and  considers
various  risk  management techniques, including the netting of foreign  currency
receipts  and  disbursements, rate protection agreements with  customers/vendors
and derivatives arrangements, including foreign exchange contracts.  The Company
presently   does   not   utilize  rate  protection  agreements   or   derivative
arrangements.

Recently Issued Accounting Standard

The  Financial Accounting Standards Board recently issued Statement of Financial
Accounting Standards ("SFAS") No. 133, Accounting for Derivative Instruments and
Hedging  Activities,  which establishes accounting and reporting  standards  for
derivative  instruments,  including certain derivative instruments  embedded  in
other  contracts  (collectively  referred to as derivatives),  and  for  hedging
activities.  This Statement is effective for all fiscal quarters of fiscal years
beginning  after June 15, 1999.  The adoption of this Statement is not  expected
to  have  a material impact on the Company's consolidated financial position  or
results of operations.

Year 2000 Readiness Disclosure Statement

Many computer systems were not designed to handle any dates beyond the year 1999
and,  therefore,  many  companies  will be required  to  modify  their  computer
hardware  and  software  prior  to  the year  2000  in  order  to  remain  fully
operational.   During 1998, the Company commenced a year 2000 readiness  program
to  assess  the  impact of the year 2000 issue on the Company's  operations  and
address  necessary remediation.  A year 2000 program director reporting directly
to senior management has been assigned to this project.

Assessment of the Company's Products for Year 2000 Compliance
All  of the Company's hardware products and accessories are year 2000 compliant,
meaning  that  they  have  been tested to verify  that  where  date  fields  are
processed,  dates  are calculated and displayed accurately, and  that  scheduled
events  such as shutdowns, self-tests, and run-time calibrations, and  also  the
handling  of unscheduled events, such as power failures, are unaffected  by  the
millenium  and  century  change; provided that all other  third  party  products
(e.g.,  software,  firmware, operating systems, and hardware) properly  exchange
date  data with the Company product and provided also that the Company  products
are  used  in  accordance  with  the product documentation.   In  addition,  the
Company's  year 2000 compliant products recognize the year 2000 as a leap  year.
The  Company  has  also tested its software products and determined  that  these
products  are  substantially year 2000 compliant, and  the  Company  intends  to
resolve  any  remaining  year 2000 issues before the  beginning  of  the  fourth
quarter  of 1999.  Periodically updated information about the Company's software
products  is available at the Company's Year 2000 Readiness Disclosure Web  site
(www.APCC.com).  Information on this site is provided to the Company's customers
for  the sole purpose of assisting in planning for transition to the year  2000.
Such information is the most currently available concerning the behavior of  the
Company's products in the next century and is provided "as is" without  warranty
of  any  kind.   In addition, to the extent the Company's hardware and  software
products  are  combined  with  the  hardware  and  software  products  of  other
companies,  there can be no assurance that users of the Company's products  will
not  experience  year  2000  problems as a result  of  the  combination  of  the
Company's  hardware and software products with non-compliant products  of  other
companies.   The Company currently does not anticipate material expenditures  to
remedy any year 2000 issues with its products and services.

Assessment of the Company's Information Technology ("IT") and Non-IT Systems for
Year 2000 Compliance
The  Company  is  currently  in the process of evaluating  its  IT  systems  for
compliance.   The  Company's  Oracle  manufacturing  and  financial  information
systems  were implemented during 1998.  The Company is evaluating the year  2000
compliance  of  these  systems in accordance with Oracle's recommendations.   At
December  31,  1998,  the  Company had completed its  initial  installation  and
testing  of  software patches available from Oracle.  The Company  is  currently
continuing  to  install  and test additional software  patches  as  they  become
available  from  Oracle.  The Company does not consider  the  cost  of  the  new
hardware and software for the Oracle implementations to be related to year  2000
readiness  as  these  system replacements were already planned  to  satisfy  the
demands of expansion of its worldwide operations and were not accelerated due to
year  2000  issues.  The Company is also currently in the process of  evaluating
its  non-IT  systems for compliance.  Additionally, the Company  utilizes  other

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third  party  software and equipment to distribute its products as  well  as  to
operate  other aspects of its business.  The Company is reviewing such  software
and  equipment.  The Company's review process is expected to be completed before
the  beginning  of the fourth quarter of 1999.  There can be no  assurance  that
such  software and equipment is year 2000 compliant, that non-compliant software
and  equipment will be made compliant on a timely basis, or that any  such  non-
compliant software and equipment would not have a material adverse effect on the
Company's systems and operations.

Evaluation  of Third Parties with which the Company has a Material Relationship,
including Key Suppliers, Service Providers, and Strategic Partners
The  Company's  year  2000  readiness program includes identifying  these  third
parties  and  determining, based on receipt of written verification,  review  of
publicly  available financial statement disclosures, and other means, that  such
third  parties are either in compliance or expect to be in compliance  prior  to
January 1, 2000.  The Company is currently in the process of communicating  with
its  significant  vendors,  service providers, and certain  strategic  partners.
Many  enterprises, including the Company's present and potential customers,  may
be  devoting  a  substantial portion of their information  systems  spending  to
resolving  year  2000 issues, which may result in their spending being  diverted
from applications such as the Company's products, over the next two years.

Development of Contingency Plans
The  Company is currently not in a position to determine what would be its  most
reasonably  likely worst case year 2000 scenario or any plan for  handling  such
scenario.  To date, the Company has not completed a formal contingency plan  for
non-compliance, however to the extent that further evaluation of  its  products,
its  IT and non-IT systems, or information obtained from the third parties  with
which  it has a material relationship suggests that there is a significant risk,
contingency  plans will be implemented.  Such contingency plans may include  the
development  of alternative sources for the product or service provided  by  any
non-compliant vendor.

It is the Company's policy to expense as incurred all costs associated with year
2000  readiness.  The Company has developed a separate budget for operating  and
capital  expenditures  relating year 2000 issues.   No  IT  projects  have  been
deferred  due  to year 2000 efforts.  Although the Company is not  yet  able  to
estimate  its  total  incremental  cost for  year  2000  issues,  based  on  its
preliminary review to date, the Company does not believe that the costs of  year
2000  issues  will  have  a material adverse effect on the  Company's  business,
operating  results,  or  financial condition.  Although the  Company  is  taking
measures  to address the impact, if any, of year 2000 issues, it cannot  predict
the  outcome  or  success  of its year 2000 readiness program,  or  whether  the
failure of third party systems or equipment to operate properly in the year 2000
will  have  a  material  adverse effect upon the Company's  business,  operating
results,  or  financial condition, or require the Company to incur unanticipated
material expenses to remedy any year 2000 issue.

The  foregoing discussion regarding the Company's year 2000 readiness  program's
implementation,  effectiveness,  and cost, contains  forward-looking  statements
which  are  based  on  management's expectations, determined  utilizing  certain
assumptions  of  future  events,  including third  party  compliance  and  other
factors.   However,  there can be no guarantee that these expectations  will  be
realized,   and  actual  results  could  differ  materially  from   management's
expectations.   Specific  factors  that might cause  such  material  differences
include, but are not limited to, the availability and cost of personnel  trained
in this area and other similar uncertainties, and the remediation success of the
Company's suppliers, service providers, and strategic partners.

Factors That May Affect Future Performance

Statements  contained  in  this  document which are  not  historical  facts  may
constitute  forward-looking  statements  as  that  term  is  defined  under  the
provisions  of  the  "safe harbor" section of the Private Securities  Litigation
Reform  Act  of 1995.  All forward-looking statements are subject to  risks  and
uncertainties  which could cause actual results to differ from those  projected.
The  factors  that could cause actual results to differ materially  include  the
following:   APC's  ability to successfully integrate Silcon's  operations;  the
timely  development  and acceptance of new products; ramp up  and  expansion  of
manufacturing capacity; general worldwide economic conditions; growth  rates  in
the  power protection industry and related industries, including but not limited
to  the  PC,  server, networking and enterprise hardware industries; competitive
factors  and  pricing  pressures;  changes  in  product  mix;  changes  in   the

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<PAGE>
seasonality of demand patterns; inventory risks due to shifts in market  demand;
the  effects  of  any  other  possible acquisitions; component  constraints  and
shortages; risk of nonpayment of accounts receivable; changes in customer  order
patterns  and product demand related to year 2000 purchasing issues;  impact  on
the Company's business due to internal systems or systems of suppliers and other
third  parties adversely affected by year 2000 problems; the uncertainty of  the
litigation  process  including  risk  of an unexpected,  unfavorable  result  of
current  litigation; and the risks described from time to time in the  Company's
filings with the Securities and Exchange Commission.


ITEM 3.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

The  Company,  in  the  normal course of business, is exposed  to  market  risks
relating  to  fluctuations in foreign currency exchange rates.  The  information
required  under  this section related to such risks is included in  the  Foreign
Currency  Activity section of Management's Discussion and Analysis of  Financial
Condition and Results of Operations in Item 2 of this Report and is incorporated
herein by reference.

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<PAGE>

PART II - OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS

Reference  is  made  to  the  disclosure in Part  I,  Item  3,  entitled  "Legal
Proceedings,"  of the Company's Annual Report on Form 10-K for the  fiscal  year
ended  December  31,  1998.  There have been no subsequent developments  in  the
matters  mentioned  therein or in any claims or legal  actions  arising  in  the
ordinary course of business which, the Company believes, are materially  adverse
to  the  Company, its consolidated financial position, results of operations  or
liquidity.

ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

(A)  Exhibits

Exhibit No. 27 - Financial Data Schedule (For SEC EDGAR Filing Only;
Intentionally Omitted)

(B)  Reports on Form 8-K

No  reports  on  Form  8-K  were filed by American Power Conversion  Corporation
during the quarter ended March 28, 1999.

                                                                       FORM 10-Q
                                                                  March 28, 1999


                                   SIGNATURES
                                        
                                        
      Pursuant  to the requirements of the Securities Exchange Act of 1934,  the
Registrant  has  duly  caused this report to be signed  on  its  behalf  by  the
undersigned thereunto duly authorized.
                                        
                                        
                      AMERICAN POWER CONVERSION CORPORATION
                                        
                               Date:  May 12, 1999
                                        
                                        
                               /s/ Donald M. Muir
                                        
                                 Donald M. Muir
                             Chief Financial Officer
                  (Principal Accounting And Financial Officer)

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