UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                                  FORM 10-Q/A

          (Mark One)

             [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934

               For the quarterly period ended September 30, 1998

                                      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:  0-22738

                        QUICKTURN DESIGN SYSTEMS, INC.
            (Exact name of registrant as specified in its charter)

             Delaware                                            77-0159619
 (State or other jurisdiction of                              (I.R.S. Employer
  incorporation or organization)                             Identification No.)

                55 W. Trimble Road, San Jose, California 95131
              (Address of principal executive offices) (zip code)

      Registrant's telephone number, including area code:  (408) 914-6000

                                   NO CHANGE
            -------------------------------------------------------
         (Former name or former address, if changed since last report)

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

As of October 31, 1998 there were 18,077,059 shares of the registrant's common 
stock outstanding.

This quarterly report on Form 10-Q/A contains 28 pages, of which this is page 1.

 
PART I. FINANCIAL INFORMATION
ITEM 1.  FINANCIAL STATEMENTS

                        QUICKTURN DESIGN SYSTEMS, Inc.
                Condensed Consolidated Statements of Operations
                 (amounts in thousands except per share data)
                                  (unaudited)
 
  
                                                  Three Months Ended       Nine Months Ended
                                                      September 30,           September 30,
                                                   -------------------     --------------------- 
                                                    1998        1997          1998       1997
                                                   --------    -------    ---------   ----------   
                                                                                     
Revenue
 Product revenue                                 $  15,556   $  22,174     $ 45,297   $  56,663
 Maintenance and service revenue                    10,021       7,890       27,792      21,241
                                                 ----------  ----------    ---------  -----------  
  Total revenue                                     25,577      30,064       73,089      77,904

Cost of revenue
 Cost of product revenue                             4,494      16,553       20,160      29,326
 Cost of maintenance and service revenue             2,895       2,393        8,889       4,846
                                                 ----------  ----------    ---------  -----------  
  Total cost of revenue                              7,389      18,946       29,049      34,172
                                                 ----------  ----------    ---------  -----------  
  Gross profit                                      18,188      11,118       44,040      43,732

Operating expenses
 Research and development                            5,347       5,884       17,811      17,555
 Sales and marketing                                 9,389       9,389       28,493      26,710
 General and administrative                          6,940       3,034       13,596       8,391
 Amortization of goodwill                              257         257          771         257
 Acquisition and merger related charges                 --       2,757           --       3,957
                                                 ----------  ----------    ---------  -----------
  Total operating expenses                          21,933      21,321       60,671      56,870
                                                 ----------  ----------    ---------  -----------
  Operating loss                                    (3,745)    (10,203)     (16,631)    (13,138)

Other income, net                                      734         636        2,221       1,546
                                                 ----------  ----------    ---------  -----------
 Net loss before benefit from
  income taxes                                      (3,011)     (9,567)     (14,410)    (11,592)

Benefit from income taxes                           (1,234)     (4,586)      (5,888)     (5,213)
                                                 ----------  ----------    ---------  -----------
 Net loss                                        $  (1,777)  $  (4,981)    $ (8,522)  $  (6,379)
                                                 ==========  ==========    =========  ===========

Basic and diluted net loss per share             $   (0.10) $    (0.29)    $  (0.48)  $   (0.38)
                                                 ==========  ==========    =========  =========== 
Number of shares used in earnings
 per share calculations                             17,809      17,462       17,772      16,954
                                                 ==========  ==========    =========  ===========

The accompanying notes are an integral part of these condensed consolidated financial statements.
 

                                      -2-

 
                        QUICKTURN DESIGN SYSTEMS, Inc.
            Consolidated Statements of Comprehensive Income (Loss)
                            (amounts in thousands)
                                  (unaudited)
 
 

                                                            Three Months Ended     Nine Months Ended
                                                               September 30,          September 30,
                                                            ------------------     -----------------
                                                             1998       1997        1998       1997
                                                             ----       ----        ----       ---- 
                                                                                   
Net loss                                                   $ (1,777)  $ (4,981)   $ (8,522)  $ (6,379)

Other comprehensive income (loss)
 Foreign currency translation adjustment                        (24)      (226)       (527)      (301)
                                                           ---------  ---------   ---------  ---------

 Unrealized gains on securities
  Unrealized holding gains arising during period                203         75         187         68
  Less:  reclassification adjustment
    for gain included in net loss                                (6)     ---           (15)     ---
                                                           ---------  ---------   ---------  ---------
 Net unrealized gain on securities                              197         75         172         68
                                                           ---------  ---------   ---------  ---------

 Total other comprehensive income (loss)                        173       (151)       (355)      (233)
                                                           ---------  ---------   ---------  ---------

Comprehensive loss                                         $ (1,604)  $ (5,132)   $ (8,877)  $ (6,612)
                                                           =========  =========   =========  =========

The accompanying notes are an integral part of these consolidated financial statements.
 

                                      -3-

 
                        QUICKTURN DESIGN SYSTEMS,  Inc.
                     Condensed Consolidated Balance Sheets
                   (amounts in thousands except share data)



                                                              September 30,   December 31,
                                                                  1998            1997
                                                              -------------   ------------
Assets                                                        (unaudited)
                                                                        
 Current assets
  Cash and cash equivalents                                   $     25,182    $     14,589
  Marketable securities                                             12,610          18,219
  Accounts receivable,  net of allowance for doubtful
   accounts of $1,840 in 1998 and 1997                              17,486          31,709
  Inventories                                                        6,932          10,899
  Prepaid expenses and other current assets                          4,000           4,324
  Deferred income taxes                                              8,697           8,697
                                                              ------------    ------------
   Total current assets                                             74,907          88,437
 Marketable securities                                              20,995          20,326
 Fixed assets, net                                                  12,838          11,118
 Deferred income taxes                                               5,770           5,770
 Goodwill                                                            3,856           4,627
 Other assets                                                        1,301           1,282
                                                              ------------    ------------
   Total assets                                               $    119,667    $    131,560
                                                              ============    ============
Liabilities
 Current liabilities
  Short term debt                                             $         --    $      1,095
  Accounts payable                                                   4,841           6,231
  Accrued liabilities                                               19,618          20,351
  Deferred revenue                                                   8,460           9,617
                                                              ------------    ------------
   Total current liabilities                                        32,919          37,294
                                                              ------------    ------------
   Total liabilities                                                32,919          37,294
                                                              ------------    ------------
Stockholders' Equity
 Common stock, $.001 par value:
  Authorized:  40,000,000 shares;
  Issued and outstanding: 18,062,179 shares in 1998;
  17,606,006 shares in 1997                                             18              18
 Additional paid-in capital                                         93,751          91,122
 Deferred compensation                                                (382)           (573)
 Retained earnings (deficit)                                        (4,258)          4,264
 Accumulated other comprehensive loss                                 (920)           (565)
 Treasury stock at cost
  (195,000 shares in 1998; none in 1997)                            (1,461)             --
                                                              ------------    ------------
   Total stockholders' equity                                       86,748          94,266
                                                              ------------    ------------
   Total liabilities and stockholders' equity                 $    119,667    $    131,560
                                                              ============    ============
 
The accompanying notes are an integral part of these condensed consolidated
financial statements.

                                      -4-

 
                        QUICKTURN DESIGN SYSTEMS, Inc.
                     Consolidated Statements of Cash Flows
                            (amounts in thousands)
 
 
                                                                            Nine months ended
                                                                              September 30,
                                                                        -------------------------
                                                                           1998           1997
                                                                        ----------     ----------   
                                                                                   
Cash flows from operating activities
Net loss                                                                $ (8,522)       $ (6,379)
Adjustments to reconcile net loss to net cash
provided by operating activities
  Depreciation and amortization                                            5,962           6,332
  Amortization of deferred compensation                                      108             146
  Gain on sale of marketable securities                                      (15)            ---
  Write off of Arkos Acquisition                                             ---           8,288
  Write down of inventories                                                  ---           4,602
  Deferred taxes                                                             ---          (4,586)
Changes in current assets and liabilities
  Accounts receivable                                                     14,223          (3,763)
  Inventories                                                              3,967          (4,199)
  Prepaid expenses and other current assets                                  324             327
  Accounts payable and accrued liabilities                                (2,122)          4,472
  Deferred revenue                                                        (1,157)         (1,270)
                                                                        --------        -------- 
       Net cash provided by operating activities                          12,768           3,970
                                                                        --------        -------- 
Cash flows from investing activities
  Acquisition of fixed assets                                             (6,763)         (5,077)
  Sale of marketable securities                                           23,871          12,055
  Purchase of marketable securities                                      (18,744)        (16,235)
  Purchase of Arkos Design, Inc.                                             ---          (5,000)
  Increase (decrease) in other assets                                       (169)          1,279
                                                                        --------        -------- 
       Net cash used in investing activities                              (1,805)        (12,978)
                                                                        --------        -------- 
Cash flows from financing activities
  Payment of debt                                                         (1,095)         (2,065)
  Proceeds from stock issuances                                            2,713           2,974
  Repurchase of treasury shares                                           (1,461)            ---
                                                                        --------        -------- 
       Net cash provided by financing activities                             157             909
                                                                        --------        -------- 

Effect of exchange rates on cash and cash equivalents                       (527)           (301)

Net increase (decrease) in cash and cash equivalents                      10,593          (8,400)
Cash and cash equivalents at beginning of year                            14,589          25,790
                                                                        --------        -------- 
Cash and cash equivalents at end of period                              $ 25,182        $ 17,390
                                                                        ========        ======== 
Supplemental disclosure of cash flow information
  Cash paid during the period for:
   Interest                                                             $     51        $    232
   Income taxes                                                         $    497        $  2,494
Supplemental disclosure of noncash investing and financing activities     
  Unrealized holding gains on marketable securities                     $    187        $     68
  Increase in inventory reserves related to Arkos Acquisition           $    ---        $  4,172
  Goodwill and other assets acquired in Arkos Acquisition               $    ---        $  5,782
  Common stock and warrants issued in Arkos Acquisition                 $    ---        $  9,500
 
The accompanying notes are an integral part of these consolidated financial 
statements.

                                      -5-

 
                        QUICKTURN DESIGN SYSTEMS, Inc.
             NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS


1.  Basis of Presentation
    The condensed consolidated financial statements are unaudited (except for
    the balance sheet information as of December 31, 1997, which is derived from
    the Company's audited financial statements) and reflect all adjustments
    (consisting only of normal recurring adjustments) which are, in the opinion
    of management, necessary for a fair presentation of the financial position
    and operating results for the interim periods. The condensed consolidated
    financial statements should be read in conjunction with the consolidated
    financial statements and notes thereto, together with Management's
    Discussion and Analysis of Financial Condition and Results of Operations
    contained in the Company's 1997 Annual Report to Stockholders. The results
    of operations for the nine months ended September 30, 1998 are not
    necessarily indicative of the results for the entire fiscal year ending
    December 31, 1998, or any future interim period.

2.  Inventories
    Inventories comprise:

 
 
                                     September 30,          December 31,
    (in thousands)                      1998                   1997
    --------------------------------------------------------------------
                                     (unaudited)
                                                        
    Raw materials                      $5,937                  $ 6,780
    Work in process                       995                    4,119
                                       ------                  -------
                                       $6,932                  $10,899
                                       ======                  =======
 

    In the second quarter of 1998, the Company incurred inventory obsolescence
    charge of $5.7 million in connection with the introduction of its
    Mercury(TM) Design Verification System.

3.  Reclassification
    Certain prior year amounts have been reclassified to conform to the current 
    year presentation.

4.  Restatement
    Quickturn has restated its accounting for the Arkos Acquisition as of
    December 31, 1997 and the year then ended. The financial statements have
    been restated to reflect a change in the allocation of the purchase price.
    As a result of this restatement, the company recognized goodwill of $5.1
    million, which is being amortized over a period of five years. These changes
    resulted in a charge for the amortization of goodwill of $257,000 and a
    related income tax benefit of $105,000, and amortization of $771,000 and a
    related tax benefit of $296,000 in

                                      -6-

 
     the third quarter and first nine months of 1998, respectively.

5.   Recent Accounting Pronouncement
     In October 1997, the Accounting Standards Executive Committee of the
     American Institute of Certified Public Accountants issued Statement of
     Position 97-2, "Software Revenue Recognition" ("SOP 97-2"). This statement
     delineates the accounting for software product and maintenance revenues. It
     supersedes Statement of Position 91-1, "Software Revenue Recognition," and
     is effective for transactions entered into in fiscal years beginning after
     December 15, 1997. The Company has evaluated the requirements of SOP 97-2,
     as amended by Statement of Position 98-4, "Deferral of the Effective Date
     of Provisions of SOP 97-2, Software Revenue Recognition," and believes its
     revenue recognition policy is in compliance with the terms of the current
     pronouncements.

     In June 1998, the Financial Accounting Standards Board issued Statement of
     Financial Accounting Standards No. 133, "Accounting for Derivative
     Instruments and Hedging Activities" ("SFAS 133"), which establishes
     accounting and reporting standards for derivative instruments and hedging
     activities. SFAS 133 requires that an entity recognize all derivatives as
     either assets or liabilities in the balance sheets and measure those
     instruments at fair value. This statement becomes effective for the Company
     for fiscal years beginning after December 15, 1999. The Company is
     evaluating the requirements of SFAS 133 and the effects, if any, on the
     Company's current reporting disclosures.

6.   Stock Purchase Program
     In April 1998, the Board of Directors authorized the repurchase of shares
     of the Company's common stock, at management's discretion, for total
     expenditures of up to $10 million. Shares repurchased under this program
     are expected to be used for issuance upon exercise of employee stock
     options previously granted or to be granted in the future under the
     Company's employee stock plans, thereby reducing the potential dilution
     that might otherwise result from such exercises. The Company's repurchases
     of shares of common stock are recorded as "Treasury stock at cost" and
     result in a reduction of Stockholder's Equity. As of September 30, 1998,
     195,000 shares of common stock at an average per share costs of $7.494 had
     been repurchased under this Stock Repurchase Program.

7.   Stock Option Repricing
     In June 1998, the Company offered employees the right to cancel certain
     outstanding stock options at their original exercise prices and receive new
     options with a new exercise price. The new exercise price is $7.438 per
     share, based on the closing price of the common stock on the last trading
     day prior to the date

                                      -7-

 
individual employees accepted the repricing offer. Options to purchase a total 
of 1,546,503 shares at original exercise prices ranging from $7.813 to $19.000 
per share were cancelled and new options to purchase an equivalent number of 
shares were issued in June 1998.  Vesting under the new options commences on the
original vesting dates, and occurs over a new vesting period of five years. 
Furthermore, the Company amended its stock option plans to require stockholders'
approval of future repricing of stock options: See "- Part II., Item 6.(a) 
Exhibit 10.1 1996 Supplemental Stock Plan, as amended" and "- Part II., Item 
6.(a) Exhibit 10.2 1997 Stock Option Plan, as amended."

                                      -8-

 
8. Earnings per Share
   Basic and diluted earnings per share were calculated as follows:

 
 
                                               Three Months Ended September 30,    
                              -------------------------------------------------------------
                                          1998                           1997
                              ----------------------------   ------------------------------
                                                                 
(unaudited)
(amounts in thousands          Net               Per-share     Net                Per-share
 except per-share data)       Loss     Shares     Amount       Loss      Shares     Amount
   ------------------------------------------------------   --------------------------------
   
Net loss               $  (1,777)                         $  (4,981)

Basic and Diluted EPS
Loss available to      ---------                          ---------                                         
common stockholders    $  (1,777)    17,809    $  (0.1)   $  (4,981)    17,462    $   (0.29)
                       =========     ======    =======    =========     ======    ========= 



 
                                             Nine Months Ended September 30,
                              -------------------------------------------------------------
                                          1998                           1997
                              ----------------------------   ------------------------------
                                                                 

(unaudited)
(amounts in thousands          Net               Per-share     Net                Per-share
 except per-share data)       Loss     Shares     Amount       Loss      Shares     Amount
   ------------------------------------------------------   --------------------------------

 Net loss              $  (8,522)                         $  (6,379)

Basic and Diluted EPS                                                 
Loss available to      ---------                           ---------    
common stockholders    $  (8,522)    17,772    $ (0.48)   $  (6,379)    16,954     $  (0.38)     
                       =========     ======    =======     =========    ======     ========
 


 At September 30, 1998 and 1997, options to purchase 3,684,405 and 3,357,607
 shares of common stock, respectively, and, warrants for 1,200,000 shares of
 common stock, were outstanding but not included in the calculation of diluted
 earnings per share because their inclusion would have been anti-dilutive.

                                      -9-

 
9. Comprehensive Income
   Effective in the first quarter of 1998, the Company has adopted Statement of
   Financial Accounting Standard No. 130, "Reporting Comprehensive Income"
   ("SFAS 130"). Comprehensive income generally represents all changes in
   stockholders' equity except those resulting from investments or contributions
   by stockholders. The Company has reclassified earlier financial statements
   for comparative purposes. The adoption of this standard did not have a
   material impact on the Company's results of operations.

   There were no tax effects allocated to the components of other comprehensive
   loss for the nine months ended September 30, 1998 and 1997.

   Changes in accumulated other comprehensive loss balances are as follows:


 
                               Foreign        Net Unreal       Accumulated
                               Currency         Gain on           Other
   (unaudited)                Translation     Marketable      Comprehensive
   (in thousands)             Adjustment      Securities           Loss
   ------------------------------------------------------------------------
                                                     
   For the Nine Months Ended September 30, 1998:

   Balance, December 31, 1997  $      (653)   $      88       $     (565)
     Current-period change            (527)         172             (355)
                               ------------   ---------       -----------
   Balance, September 30, 1998 $    (1,180)   $     260       $     (920)
                               ============   =========       ===========

10. Bank Borrowing Arrangements
    The Company has an unsecured revolving line of credit totaling $5.0 million
    which provides for borrowings through June 1, 1999. The Company is currently
    in compliance with the covenants of this borrowing agreement. To date, no
    funds have been drawn against the line of credit.
 

                                     -10-

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

Results of Operations

Total Revenue
The Company's 1998 third quarter total revenue of $25.6 million represented a
15% decrease compared to the third quarter total revenue of the prior year.
Total revenue for the first nine months of 1998 of $73.1 million decreased 6%
compared to the first nine months of the prior year.  The decreases in total
revenue were attributable primarily to lower product sales in the Asia-Pacific
region and certain segments of the U.S. market, particularly those customers
that are heavily dependent on sales to the Asia-Pacific region, partially offset
by increases in maintenance and service revenue.  See "---Risk Factors:
International Sales", "---Risk Factors:  Potential Fluctuations in Quarterly
Results", "---Risk Factors:  Customer Concentration", "---Risk Factors:  New
Product Transition", "---Risk Factors:  Software Revenue Recognition" and "---
Risk Factors:  Dependence Upon Certain Suppliers."

Product revenue for the third quarter of the current year decreased by 30% from
the third quarter of 1997.  For the first nine months of the current year,
product revenue decreased by 20% from the first nine months of the prior year.
The decreases in product revenue were primarily driven by the weakness in the
Asia-Pacific market and its indirect adverse effect on the U.S. market, as
discussed above.

Maintenance and service revenue for the third quarter of the current year
increased by 27% over the third quarter of 1997.  For the first nine months of
the current year, maintenance and service revenue increased by 31% over the
first nine months of the prior year.  The increases in maintenance and service
revenue were attributable primarily to a larger number of maintenance contracts
on customers' installed systems and to increased sales of the Company's custom
engineering services.

International revenue accounted for approximately 28% and 35% of total revenue
in the third quarters of 1998 and 1997, respectively.  For the first nine months
of 1998 and 1997, international revenue was approximately 27% and 34% of total
revenue, respectively.  The decrease in international revenue as a percentage of
total revenue for the third quarter of 1998 was due primarily to decreased sales
in both the Asia-Pacific and European regions in the third quarter of 1998.  The

                                      -11-

 
decrease in international revenue as a percentage of total revenue for the first
nine months of 1998 was due primarily to lower sales in Asia-Pacific, slightly
offset by overall increased sales in Europe in the first nine months of 1998.
Revenue in the Asia-Pacific region decreased by 39% in the third quarter of 1998
compared to the third quarter of 1997, and decreased by 47% in the first nine
months of 1998 compared to the first nine months of 1997.  See "---Risk Factors:
International Sales."

Gross Margins
Gross margins were 71% in the third quarter of 1998 compared with 37% in the
same quarter of the prior year. Gross margins in the third quarter and first 
nine months of 1997 were impacted by $7.4 million of sales at zero gross margin
related to the Arkos Acquisition, a $2.6 million write off of Arkos purchased
inventory and a $2.0 million inventory obsolescence charge caused by an
anticipated shorter product life cycle of Quickturn's System Realizer emulation
product resulting from the effect of Arkos-related technology. Excluding these
charges in 1997, gross margins were 71% in the third quarters of both years.
Gross margins in the first nine months of the current year were 60%, which
included an inventory obsolescence charge of $5.7 million resulting from the
introduction of the Company's Mercury Design Verification System ("Mercury") in
the second quarter of the current year. Excluding the inventory item mentioned
above and the effect of the Arkos Acquisition, gross margins in the first nine
months of 1998 were 68% as compared to 69% in the first nine months of 1997. The
decrease in gross margins in the first nine months of 1998, excluding the items
mentioned above, was attributable primarily to decreased maintenance and service
gross margins due to increased field support requirements to service new and
existing contracts. See "---Risk Factors: Gross Margins."

Research and Development
Research and development expenses decreased by 9% in the third quarter of 1998
compared to the third quarter of the prior year.  This decrease was attributable
primarily to reduced hardware prototype expenses for the new Mercury product in
the third quarter of 1998 as compared to the third quarter of 1997.  As a
percentage of total revenue, research and development expenses were
approximately 21% and 20% for the third quarters of the current year and prior
year, respectively.  For the first nine months of the current year and prior
year, research and development expenses were 24% and 23% of total revenue,
respectively.  The Company expects to continue to invest a significant amount of
its resources in research and development.

                                      -12-

 
Sales and Marketing
Sales and marketing expenses were flat for the third quarter of 1998 compared to
the third quarter of the prior year.  As a percentage of total revenue, sales
and marketing expenses were approximately 37% and 31% in the third quarters of
the current year and prior year, respectively.  For the first nine months in the
current year and prior year, sales and marketing expenses were 39% and 34% of
total revenue, respectively.  The Company expects that sales and marketing
expenses will continue to increase in dollar amounts as the Company expands its
sales and marketing efforts.

General and Administrative
General and administrative expenses increased by 129% in the third quarter of
1998 compared to the third quarter of the previous year.  This increase was due
largely to legal and advisory expenses of $4.0 million related to an unsolicited
tender offer in the third quarter of 1998, and increased legal costs related to
ongoing patent infringement and other legal proceedings.  See "---Part II., Item
1. Legal Proceedings." As a percentage of total revenue, general and
administrative expenses were approximately 27% and 10% for the third quarters of
the current year and prior year, respectively.  For the first nine months of the
current year and prior year, general and administrative expenses were 19% and
11% of total revenue, respectively.  The Company expects general and
administrative expenses to increase in 1998 due primarily to continued legal
costs.

Acquisition and Merger Related Charges
In connection with its merger with SpeedSim, Inc. (the "SpeedSim Merger"), the
Company recorded one-time charges of $1.2 million in the first quarter of 1997
that included fees for investment banking, legal and accounting services and
other costs of consolidating.

In connection with the Arkos Acquisition, the Company recorded charges of $2.8
million in the third quarter of 1997 which represented the write-off of in-
process research and development of an Arkos emulator which proved to be
incompatible with the underlying technology used in Quickturn's products.

Other Income, Net
Other income, net, for the third quarter of the current year increased by 15%
over the third quarter of the prior year.  For the first nine months of the
current year, other income, net, increased by 44% over the first nine months of
the previous year.  The increases were due primarily to increased interest
income due to higher interest rates and higher average balances of cash and
marketable

                                      -13-

 
securities, and reduced interest expenses related to the decreased level of debt
associated with maturing equipment leases.

Benefit from Income Taxes
The tax benefit rates were 41% for both the third quarter and first nine months
of 1998, and 48% and 45% for the third quarter and first nine months of 1997,
respectively.  The tax benefit rates were in excess of the federal statutory
rate of 35% primarily because of federal and state general business credits and
interest income on investments in tax-exempt obligations.

Net Loss and Quarterly Results
The net loss in the third quarter of 1998 was $1.8 million, which included legal
and advisory expenses of $4.0 million related to an unsolicited tender offer, or
$2.3 million, net of tax.  See "General and Administrative" above.  Excluding
the expenses related to the tender offer, net income for the third quarter of
1998 was $583,000. In the corresponding quarter of 1997, the net loss was $5.0
million, which, included one-time charges of $12.9 million for the Arkos
Acquisition, or $7.3 million, net of tax.  See "Gross Margins" and "Acquisitions
and Merger Related Charges" above.  Excluding the Arkos Acquisition charges and
related goodwill amortization in the quarter, net income for the third quarter
of 1997 was $2.5 million. The decrease in net income, excluding the tender offer
expenses and the acquisition charges, was due primarily to a decrease in
revenue.  See "Total Revenue" above.

Liquidity and Capital Resources
Cash and cash equivalents increased by $10.6 million from December 31, 1997 to
September 30, 1998.  Net cash provided by operations was $12.8 million, due
primarily to decreased accounts receivable of $14.2 million, decreased
inventories of $4.0 million and depreciation and amortization of $6.0 million,
partially offset by a net loss of $8.5 million, decreased accounts payable and
accrued liabilities of $2.1 million, and decreased deferred revenue of $1.2
million. Net cash used in investing activities was $1.8 million, due primarily
to purchases of marketable securities of $18.7 million and for the acquisition
of fixed assets of $6.8 million, partially offset by sales of marketable
securities of $23.9 million.   Net cash provided by financing activities was
$157,000, due primarily to proceeds from stock issuances of $2.7 million,
partially offset by the repurchase of treasury shares of $1.5 million and
payments of debts of $1.1 million.

The Company believes that its cash and cash equivalents, together with its
existing credit facility and the cash flows expected to be generated by
operations, will be sufficient to meet its anticipated cash needs for working
capital, capital expenditures and marketing expansion through at least the next
12 months.

                                      -14-

 
Thereafter, if cash generated from operations is insufficient to satisfy the
Company's liquidity requirements, the Company may sell additional equity or debt
securities or obtain additional credit facilities.

Risk Factors
In addition to other information in the Company's Annual Report on Form 10-K for
the year ended December 31, 1997 and in the documents incorporated by reference
therein, the following risk factors should be carefully considered in evaluating
the Company and its business because such factors currently have a significant
impact or may have a significant impact on the Company's business, operating
results or financial condition.

Potential Fluctuations in Quarterly Results
Many of the Company's customers order on an as-needed basis and often delay
delivery of firm purchase orders until the commencement dates of such customers'
development projects are determined.  Moreover, a significant portion of the
Company's revenue in each quarter generally results from shipments in the last
few weeks of the quarter; therefore, a delay in the shipment of a few orders can
have a significant impact upon total revenue and results of operations in a
given quarter.

Customer Concentration
A relatively limited number of customers have historically accounted for a
substantial portion of the Company's revenue.  These customers represent early
adopters of emulation technology, typically utilized for the design of complex
integrated circuits.  In particular, the Company's top ten customers represented
65% and 58% of total revenue in the third quarters of 1998 and 1997,
respectively. In the first nine months of 1998 and 1997, the top ten customers
accounted for 53% and 44% of total revenue, respectively.  The Company expects
that sales of its products to a relatively limited number of customers will
continue to account for a high percentage of revenue for the foreseeable future.
The loss of a major customer or any reduction in orders by such a customer could
have an adverse effect on the Company's financial condition or results of
operations.  The Company believes that in the future its results of operations
in a quarterly period could be impacted by the timing of customer development
projects and related purchase orders for the Company's emulation systems, new
product announcements and releases by the Company, and economic conditions
generally and in the electronics industry specifically.

New Product Transition
In June 1998, the Company announced its new Mercury Design Verification System,
which is designed to replace certain of the Company's existing emulation
products.  There can be no assurance that this announcement will not

                                      -15-

 
cause customers to defer purchases of the Company's existing emulation products,
or that the transition to the new Mercury System will not be disrupted due to
slow market acceptance or due to disruptions in manufacturing or component
availability, all of which could materially adversely affect the Company's
results of operations.

Software Revenue Recognition
In October 1997, the Accounting Standards Executive Committee of the American
Institute of Certified Public Accountants issued Statement of Position 97-2,
"Software Revenue Recognition" ("SOP 97-2"), which is effective for transactions
entered into in fiscal years beginning after December 15, 1997.  SOP 97-2 was
amended by Statement of Position 98-4, "Deferral of the Effective Date of
Provisions of SOP 97-2, Software Revenue Recognition."  Because of the
uncertainties related to the outcome of these pronouncements, the impact on the
future financial results of the Company is not currently determinable.

International Sales
As a significant portion of the Company's total revenue and net income are
derived from international operations, fluctuations of the U.S. dollar against
foreign currencies and the seasonality of Asia-Pacific, European, and other
international markets could impact the Company's results of operations and
financial condition in a particular quarter.

Revenue from most international customers is denominated in U.S. dollars.
However, receivables from certain other international customers are denominated
in local currencies.  Such receivables are hedged, where practicable, by forward
exchange contracts to minimize the impact of foreign exchange rate movements on
the Company's operating results. There have been no material gains or losses
associated with the Company's hedging program.  However, there can be no
assurance that fluctuations in the currency exchange rates in the future will
not have a material adverse impact on the receivables derived from foreign
currency denominated sales and thus the Company's operating results and
financial condition.  See Note 2 of the Notes to Consolidated Financial
Statements in the Company's 1997 Annual Report to Stockholders.

The Company plans to continue to expand its international sales and distribution
channels.  However, there can be no assurance that the Company's products will
achieve widespread commercial acceptance in international markets in the future.
The Company is uncertain whether the recent weakness experienced in the Asia-
Pacific markets will continue in the foreseeable future due to extreme currency
devaluation and liquidity problems in this region.  Additionally, Electronic
Design Automation ("EDA") spending budgets of major Japanese

                                      -16-

 
electronics firms have been and may continue to be decreased; consequently,
sales of the Company's design verification products in Japan may continue to be
down in the foreseeable future. The Company's future international sales may be
subject to additional risks associated with international operations, including
currency exchange fluctuations, tariff regulations and requirements for export,
which licenses may on occasion be delayed or difficult to obtain.

                                      -17-

 
Dependence Upon Certain Suppliers 
Certain key components and board assemblies used in the Company's emulation
products are presently available from sole or limited sources. The inability to
develop alternate sources for these sole or limited sources or to obtain
sufficient quantities of these components or board assemblies could result in
delays or reductions in product shipments which could adversely affect the
Company's results of operations. In particular, the Company currently relies on
Xilinx, Inc. ("Xilinx") for its supply of field programmable gate arrays
("FPGAs") and on General Dynamics for its computer board assemblies. General
Dynamics has recently informed the Company that it will terminate its board
assembly services to the Company some time in early 1999. The Company is
currently in the final stages of negotiation with IBM Corporation ("IBM") to
replace the services currently provided by General Dynamics. There can be no
assurance that these negotiations will be successfully completed or that other
disruptions might not occur during the transition from General Dynamics to IBM.
If for this or any other reason there were to be a reduction or interruption of
FPGA supply or board assemblies to the Company, the Company's results of
operations would be materially adversely affected. Although the Company believes
that it can eventually obtain FPGAs and board assemblies from alternate sources
in the event of a reduction or interruption of FPGA supply or board assemblies
from Xilinx, IBM or General Dynamics, a significant amount of time and resources
would be required to redesign the Company's emulation systems and software to
accommodate an alternate FPGA supplier or board assembler. In such event, the
Company's results of operations could be materially adversely affected. The
Company currently mitigates this risk by maintaining inventory of these
components in excess of its near-term forecasted requirements. However, there
can be no assurance that these measures will be adequate to alleviate any future
supply problems.

Gross Margins
There can be no assurance that the Company will be able to sustain its recent
gross margins.  Furthermore, to the extent that the Company's cost reduction
goals are achieved, any resulting cost savings that are passed on to the
Company's customers may also have an adverse effect on gross margins.

Competition
The EDA industry is highly competitive and rapidly changing. The Company faces
significant competition for emulation-based system-level verification and cycle-
based simulation, in addition to competition from traditional design
verification methodologies which rely on the approach of building and then
testing complete system prototypes.  Because of the growing demand for a design
verification methodology which reduces the number of costly design

                                      -18-

 
iterations and improves product quality, the Company expects competition in the
market for system-level verification and cycle-based simulation to increase as
other companies attempt to introduce emulation and cycle-based simulation
products and product enhancements, and as major new EDA technologies may emerge.
Moreover, the Company competes with companies that have significantly greater
financial, technical and marketing resources, greater name recognition and
larger installed bases than the Company. In addition, many of these competitors
have established relationships with current and potential customers of the
Company. Increased competition could result in price reductions, reduced margins
and loss of market share, all of which could materially adversely affect the
Company. The Company believes that the principal competitive factors in the EDA
market are quality of results, the mission-critical nature of the technology,
technical support, product performance, reputation, price and support of
industry standards. The Company believes that it currently competes favorably
with respect to these factors. However, there can be no assurance that the
Company will be able to compete successfully against current and future
competitors or that competitive pressures faced by the Company will not
materially adversely affect its business, operating results and financial
condition.

In addition, competitors may resort to litigation as a means of competition.
Such litigation may result in substantial costs to the Company and significant
diversion of management time.  In 1995, Mentor Graphics Corporation ("Mentor")
filed suit against the Company for declaratory judgment of non-infringement,
invalidity and unenforceability of several of the Company's patents. Several
actions between the Company and Mentor were consolidated in the U.S. District
Court for the District of Oregon, where six of the Company's patents are now
involved in the disputes.  The Company has filed counterclaims against Mentor
and Mentor's French subsidiary, Meta Systems ("Meta"), for infringement and
threatened infringement of those six patents.  Mentor has also filed claims
against the Company for defamation and tortious interference.  The Company is
also involved in litigation with Mentor's subsidiary in Germany, with Meta in
France, and with Aptix Corporation and Meta in the U.S. District Court, the
Northern District of California.  See "---Part II., Item 1. Legal Proceedings."
Although patent and intellectual property disputes in the EDA industry are often
settled through licensing, cross-licensing or similar arrangements, costs
associated with such litigation and arrangements may be substantial.

                                      -19-

 
Impact of the Year 2000 Issue
Many existing computer systems, applications and other control devices use
computer programs that recognize only two digits rather than four digits to
define an applicable year.  Therefore, any of the Company's computer systems or
other equipment with embedded date-sensitive technology may recognize a date
using "00" as the year 1900 rather than the year 2000 (the "Year 2000 Issue").
This could result in a system failure or miscalculations causing disruptions of
the Company's operations, or in the ability of the Company's customers to
effectively utilize the Company's design verification products.

The company initiated a Year 2000 Compliance project in the fall of 1997.  The
scope of this project includes addressing the Year 2000 Issue in six key areas:
(1) Quickturn's proprietary design verification products, (2) internal-use
computer systems for conducting business operations and product development, (3)
internal embedded systems or "infrastructure", (4) third-party suppliers of
products and services, (5) customers, and (6) marketing joint ventures and other
partnerships.  The project consists of addressing these six areas in four
phases, which are:  (1) planning, (2) investigation, (3) remediation, and (4)
testing.

The Company has completed the planning phase, which involved identifying and
documenting all areas where material disruption of the Company's activities
might occur in case of Year 2000 failure and implementing a plan to remediate
these problems.  A project team (the "Year 2000 Committee") is formally
chartered with carrying out the Project.  The Year 2000 Committee reports
regularly to the Company's Board of Directors.

To date, the Company has also substantially completed the investigation phase in
all six areas.  The investigation includes specifically identifying computer and
other systems, including Quickturn verification products and third party systems
used in Quickturn products and in business operations, that are vulnerable to
Year 2000 failure. During this phase, the Company substantially completed formal
communications with its significant suppliers to determine the extent to which
the Company is vulnerable to those third parties' failure to remedy their own
Year 2000 Issue.  Computer equipment and embedded-systems vendors, business
service providers and other third-party vendors on whom the Company relies to
carry out normal business operations generally have indicated substantial
compliance with, or awareness of, the Year 2000 issue.  However, the Company's
operations could be materially affected if certain utilities, government
entities or private businesses that interface with these entities are not Year
2000 compliant.  To date, the Company cannot be certain that such entities will
achieve Year 2000 compliance.

                                      -20-

 
Based on the results of the investigation phase, the Company has determined that
it will be required to modify or replace certain portions of its software so
that its computer systems and design verification products will properly utilize
dates beyond December 31, 1999. The Company presently believes that, with
modifications to existing software or conversion to new software, the Year 2000
Issue can be mitigated.  However, if such modifications and/or conversions are
not made, the Year 2000 Issue could have a material impact on the operations of
the Company.  There can be no assurance that the systems of third parties on
which the Company's systems and business operations rely will be converted in a
timely fashion, or that a failure to convert by a third party, or a conversion
that is incompatible with the Company's systems, would not have a material
adverse effect on the Company.

To mitigate such third party issues, the Company is currently addressing
contingency plans in the event of any material third party failure to comply.
Contingency plans may include such things as stockpiling raw materials, seeking
alternate suppliers, using alternate operating sites or backup systems, or other
measures.

To date, the Company has substantially completed the remediation phase with
respect to internal-use computer hardware and software and embedded systems.  A
majority of the critical business and development computer systems have been
remediated and are in the testing phase.  Testing of these systems is expected
to be completed by March 1999.  Quickturn verification product remediation is
currently under way, with final compliance estimated to be achieved by mid-1999
for all current product lines and for those products that may be introduced by
that date. Year 2000 remediation efforts are not expected to materially impact
or delay the Company's other information technology ("IT") projects or new
product introductions.  In addition, the Company intends to closely monitor the
remediation efforts by third party business service providers, customers and
partners.  However, there can be no assurance that the efforts of these third
parties will be successful and that their failure to comply will not materially
impact the operations of the Company.

The costs to complete the Year 2000 project are based on management's best
estimates.  Management currently estimates the total costs of the Year 2000
project at $500,000. The Company is utilizing both internal and external
resources to reprogram, or replace, and test software for Year 2000
modifications.  These costs have been and will be absorbed substantially in the
research and development and IT functions.  Estimated costs incurred to date for
the Year 2000 Issue modifications are $120,000, all of which have been expensed
in the period incurred.  Estimated costs do not include the costs associated
with

                                      -21-

 
contingency plans, which are currently being developed. There can be no
assurance that these cost estimates will be achieved and actual results could
differ materially from these estimates. Specific factors that might cause such
material difference include, but are not limited to, the availability and cost
of personnel trained in this area, the ability to locate and correct all
relevant computer code, the failure of third parties which are material to the
Company's operations to mitigate their own Year 2000 Issue, and similar
uncertainties. However, the Company is vigilantly pursuing the Year 2000 Issue,
and believes, that once all phases of the project have been completed and
contingency plans have been explored and put in place, the Company will be able
to significantly reduce the impact of any disruptions that may occur due to this
issue.

Derivative Instruments and Hedging Activities
In June 1998, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 133, "Accounting for Derivative Instruments
and Hedging Activities" ("SFAS 133"), which establishes accounting and reporting
standards for derivative instruments and hedging activities.  SFAS 133 requires
an entity to recognize all derivatives as either assets or liabilities in the
balance sheets and measure those instruments at fair value.  This statement
becomes effective for the Company for fiscal years beginning after December 15,
1999.  The Company is evaluating the requirements of SFAS 133 and the effects,
if any, on the Company's current reporting and disclosures.

Unsolicited Tender Offer
On August 12, 1998, a subsidiary of Mentor Graphics Corporation initiated an
unsolicited tender offer (the "Tender Offer") to purchase all outstanding shares
of the Company's common stock.  The Tender Offer has had, and may continue to
have, various adverse effects on the Company's business and results of
operations, including the increased susceptibility of key employees of the
Company to employment offers by other companies, the risk of negative reactions
among distributors, suppliers or customers of the Company to the prospect of
such a change in control of the Company, the distraction of management and other
key employees and the fees and other expenses of financial, legal and other
advisors to the Company in responding to the tender offer and related legal
actions.

                                      -22-

 
Other Risk Factors
Other factors which could adversely affect the Company's quarterly operating
results in the future include efficiencies as they relate to managing
inventories and fixed assets, the timing of expenditures in anticipation of
increased sales, customer product delivery requirements and shortages of
components or labor.

Due to the factors above, the Company's future earnings and stock price may be
subject to significant volatility, particularly on a quarterly basis. Any
shortfall in total revenue or earnings from levels expected by securities
analysts has had and could in the future have an immediate and significant
adverse effect on the trading price of the Company's common stock. Additionally,
the Company may not learn of such shortfalls until late in a fiscal quarter,
which could result in an even more immediate and adverse effect on the trading
price of the Company's common stock.


ITEM 3 is not applicable and has been omitted.

                                      -23-

 
PART II.  OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

In January 1996, the Company filed a complaint with the International Trade
Commission (the "ITC") in Washington, DC, seeking to stop unfair importation of
logic emulation systems manufactured by Meta Systems ("Meta"), a French
subsidiary of Mentor Graphics Corporation ("Mentor").  In the complaint, the
Company alleges that Mentor's hardware logic emulation systems infringe the
Company's patents.  In December 1997, the ITC issued: (1) a Permanent Limited
Exclusion Order which permanently prohibits the importation of hardware logic
emulation system, subassemblies or components manufactured by Mentor and/or
Meta, and (2) a Permanent Cease and Desist Order permanently prohibiting Mentor
from, among other things, selling, offering for sale or advertising the same
hardware logic emulation devices.  The ITC's two orders remain in effect until
April 28, 2009, the latest expiration date of the Company's patents involved in
the investigation.

The Company is also engaged in a Federal District Court case with Mentor and
Meta involving six of the Company's patents.  Mentor and Meta are seeking a
declaratory judgment of noninfringement, invalidity and unenforceability of the
patents in dispute, and the Company has filed counteractions against Mentor and
Meta for infringement and threatened infringement of the six patents.  Mentor
has also claimed in this Federal District Court case that press releases issued
by the Company were defamatory and interfered with Mentor's prospective economic
relations.  In June 1997, Quickturn filed a motion for preliminary injunction,
asking the District Court to prohibit Mentor from manufacturing, assembling,
marketing, loaning or otherwise distributing emulation products and components
in the United States, which products and components infringe certain claims in
Quickturn's U.S. Patent No. 5,036,473.  On August 1, 1997, the U.S. District
Court in Oregon granted Quickturn's motion for a preliminary injunction against
Mentor's domestic emulation activities.  The Federal Circuit Court of Appeals
affirmed the Oregon District Court's decision on August 5, 1998.  The Oregon
action is presently set for trial in January 1999.

In October 1997, the Company filed a complaint alleging infringement of the
German part of the Company's European Patent No. 0 437 491 B1 against Mentor
Graphics (Deutschland) GmbH, in the District Court of Dusseldorf.  The main
court hearing for this matter is set for March 1999.

In November 1996, Aptix Corporation ("Aptix") filed a suit against the Company,
in the U.S. District Court, the Northern District of California, alleging

                                      -24-

 
various violations of the antitrust laws and unfair competition. The District
Court granted a summary judgment motion in favor of the Company and dismissed
the case. Aptix has requested the Court to reconsider its decision and
dismissal.

In February 1998, Aptix and Meta filed a lawsuit against the Company, in the
U.S. District Court, the Northern District of California, alleging infringement
of a U.S. patent owned by Aptix and licensed to Meta.  The Company named Mentor
as a party to this suit and filed a counter claim requesting the Court to
declare the Aptix patent to be unenforceable based on inequitable conduct during
the prosecution of the patent.  The Company also requested permission from the
Court to bring a claim against Aptix, Meta and Mentor for abuse of process.  The
case is currently in the discovery phase.

In October 1998, the Company filed a complaint alleging infringement of the
French part of the Company's European Patent No. 0 437 491 B1 against Mentor
Graphics (France) SARL, Meta Systems (France), a subsidiary of Mentor Graphics
Corporation, and Mentor Graphics (Netherlands) BV, in the District Court of
Paris.

The Company has mounted vigorous defenses against Mentor's defamation and
tortious interference claims and against Aptix and Meta's patent infringement
claim.  The outcome of these actions cannot be predicted with certainty.

The Company is engaged in certain other legal and administrative proceedings
incidental to its normal business activities.  While it is not possible to
determine the ultimate outcome of these actions at this time, management
believes that any liabilities resulting from such proceedings, or claims which
are pending or known to be threatened, will not have a material adverse effect
on the Company's consolidated financial position or results of operations.

In addition to the legal proceedings described above, the Company is engaged in
legal proceedings with Mentor Graphics Corporation in connection with the Tender
Offer.  These legal proceedings are described more fully in the Company's
filings with the Securities and Exchange Commission on Schedule 14D-9 and the
amendments thereto.

                                      -25-

 
ITEM 5.  OTHER INFORMATION

On August 24, 1998 the board of directors of the Company announced its decision
to recommend that the Company's stockholders reject Mentor Graphics
Corporation's unsolicited tender offer for all outstanding shares of the
Company's common stock.  The Company and Mentor Graphics Corporation are
currently engaged in patent and other litigation concerning various matters,
including the tender offer.  For more information, see the Company's filings
with the Securities and Exchange Commission under Sections 14(a) and 14(d) of
the Securities and Exchange Act of 1934.

                                      -26-

 
ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

(a)  Exhibits

   Exhibit 3.2:  *  Bylaws of the Registrant, as amended through August 21,
1998.

   Exhibit 10.1:  * 1996 Supplemental Stock Plan, as amended.

   Exhibit 10.2:  * 1997 Stock Option Plan, as amended.

   Exhibit 27:      Financial Data Schedule.

* previously filed

(b)  Report on Form 8-K

     No reports on Form 8-K were filed in the quarter ended September 30, 1998.


ITEMS 2, 3 and 4 are not applicable and have been omitted.

                                      -27-

 
                                  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.

                                QUICKTURN DESIGN SYSTEMS, Inc.
                                ------------------------------
                                        (Registrant)

Date: March 29, 1999                    By: /s/ RAYMOND K. OSTBY
      ----------------------                ---------------------------
                                            Raymond K. Ostby,
                                            Vice President, Finance and
                                            Administration,
                                            Chief Financial Officer and
                                            Secretary
                                            (Principal Accounting Officer
                                            and Duly Authorized Officer)


                                     -28-