SECURITIES AND EXCHANGE COMMISSION

                              Washington, DC 20549

                                 ---------------

                                    FORM 10-Q

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

                For the Quarterly Period Ended September 30, 2002

                                       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 000-19392

                              DIANON SYSTEMS, INC.
             (exact name of registrant as specified in its charter)

                Delaware                                    06-1128081
       (State of incorporation)                (IRS Employer Identification No.)

     200 Watson Blvd, Stratford, CT                            06615
(Address of principal executive offices)                     (zip code)

       Registrant's telephone number, including area code: (203) 381-4000

                                 NOT APPLICABLE
              (Former name, former address and former fiscal year,
                          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 [ ]

The number of shares of registrant's Common Stock, $.01 par value, outstanding
on October 24, 2002 was 12,058,646 shares.


                              DIANON SYSTEMS, INC.
                                AND SUBSIDIARIES

                                      INDEX

Part I FINANCIAL INFORMATION                                            PAGE NO.
- ----------------------------                                            --------

Item 1.     FINANCIAL STATEMENTS

            Consolidated Balance Sheets as of September 30, 2002
            and December 31, 2001.                                         3

            Consolidated Statements of Operations for the three month
            and nine month periods ended September 30, 2002 and 2001.      4

            Consolidated Statements of Stockholders' Equity for the

            nine months ended September 30, 2002 and 2001.                 5

            Consolidated Statements of Cash Flows for the

            nine months ended September 30, 2002 and 2001.                 6

            Notes to Consolidated Financial Statements.                    7-10

Item 2.     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
            FINANCIAL CONDITION AND RESULTS OF OPERATIONS                  11-17

Item 3.     QUANTITATIVE AND QUALITATIVE DISCLOSURES
            ABOUT MARKET RISK                                              18

Item 4.     CONTROLS AND PROCEDURES                                        18

Part II OTHER INFORMATION
- -------------------------

Item 6.     EXHIBITS AND REPORTS ON FORM 8-K                               19

Signatures                                                                 20


                                       2


Part 1. Financial Information
Item 1. Financial Statement

                              DIANON SYSTEMS, INC.
                           CONSOLIDATED BALANCE SHEETS



                                                                                SEPTEMBER 30,       DECEMBER 31,
                                                                                    2002                2001
                                                                                -------------      -------------
                   ASSETS                                                        (UNAUDITED)
                                                                                             
CURRENT ASSETS:
      Cash and cash equivalents                                                 $   8,884,226      $  41,229,353
      Available-for-sale securities                                                51,167,259          1,071,778
      Accounts receivable, net of allowances                                       38,088,090         29,863,129
      Prepaid expenses and other current assets                                     3,105,272          3,767,086
      Prepaid / refundable income taxes                                             2,829,469          5,753,944
      Inventory                                                                     2,189,042          1,932,713
      Deferred income taxes                                                         5,896,064          6,560,564
                                                                                -------------      -------------
        Total current assets                                                      112,159,422         90,178,567
                                                                                -------------      -------------
PROPERTY AND EQUIPMENT, at cost
      Laboratory and office equipment                                              21,655,622         19,539,228
      Leasehold improvements                                                        9,394,342          8,967,113
         Less - accumulated depreciation and amortization                         (20,494,175)       (17,650,512)
                                                                                -------------      -------------
                                                                                   10,555,789         10,855,829
                                                                                -------------      -------------
INTANGIBLE ASSETS, net of accumulated amortization of
        $5,194,879 and $3,662,150, respectively                                   182,581,174        183,167,116
DEFERRED INCOME TAXES                                                                      --          2,429,417
OTHER ASSETS                                                                          790,694            787,230
                                                                                -------------      -------------
        TOTAL ASSETS                                                            $ 306,087,079      $ 287,418,159
                                                                                =============      =============

                   LIABILITIES AND STOCKHOLDERS' EQUITY
CURRENT LIABILITIES:
      Accounts payable                                                          $   1,926,461      $   1,621,689
      Accrued employee compensation                                                 4,934,657          6,961,747
      Current portion of capitalized lease obligations                                217,562            300,102
      Other accrued expenses                                                       15,447,292         12,459,309
                                                                                -------------      -------------
        Total current liabilities                                                  22,525,972         21,342,847
                                                                                -------------      -------------
LONG-TERM LIABILITIES:
      Deferred income taxes                                                         1,168,729                 --
      Long-term portion of capitalized lease obligations                               36,903            439,029
                                                                                -------------      -------------
        Total Liabilities                                                          23,731,604         21,781,876
                                                                                -------------      -------------
STOCKHOLDERS' EQUITY:
      Common stock, par value $.01 per share, 55,000,000 shares authorized,
         12,352,012 and 11,896,140 shares issued and outstanding
         at September 30, 2002 and December 31, 2001, respectively                    123,520            118,961
      Additional paid-in capital                                                  256,539,509        242,987,849
      Retained earnings                                                            35,064,597         22,620,561
      Common stock held in treasury, at cost - 294,289 and 9,511
         shares at September 30, 2002 and December 31, 2001, respectively         (10,164,191)           (91,088)
      Accumulated other comprehensive income                                          792,040                 --
                                                                                -------------      -------------
         Total stockholders' equity                                               282,355,475        265,636,283
                                                                                -------------      -------------
           TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY                           $ 306,087,079      $ 287,418,159
                                                                                =============      =============


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

                                       3


                              DIANON SYSTEMS, INC.
                      CONSOLIDATED STATEMENTS OF OPERATIONS
                FOR THE THREE MONTH AND NINE MONTH PERIODS ENDED
                           SEPTEMBER 30, 2002 and 2001

                                   (UNAUDITED)



                                                       THREE MONTHS ENDED                   NINE MONTHS ENDED
                                                          SEPTEMBER 30,                       SEPTEMBER 30,
                                                     2002              2001              2002               2001
                                                 -------------     -------------     -------------      -------------
                                                                                            

Net revenues                                     $  47,084,753     $  28,940,906     $ 140,965,249      $  84,505,918

Cost of sales                                       23,374,450        16,095,217        70,247,328         46,931,286
                                                 -------------     -------------     -------------      -------------

     GROSS PROFIT                                   23,710,303        12,845,689        70,717,921         37,574,632

Selling, general and administrative expenses        13,472,065         8,526,412        40,384,893         24,759,535

Special charge                                       5,450,000                --         5,450,000                 --

Special credit for bad debts                                --                --          (710,957)                --

Amortization of intangible assets                      640,378           338,701         1,532,729          1,016,100

Research and development expenses                      270,523           286,899         1,037,739            954,431
                                                 -------------     -------------     -------------      -------------

     INCOME FROM OPERATIONS                          3,877,337         3,693,677        23,023,517         10,844,566

Interest income, net                                   521,515           184,352         1,158,056            457,152
                                                 -------------     -------------     -------------      -------------

    INCOME BEFORE PROVISION FOR
        INCOME TAXES                                 4,398,852         3,878,029        24,181,573         11,301,718

Provision for income taxes                           3,725,535         1,570,602        11,737,537          4,577,196
                                                 -------------     -------------     -------------      -------------

     NET INCOME                                  $     673,317     $   2,307,427     $  12,444,036      $   6,724,522
                                                 =============     =============     =============      =============

     EARNINGS PER SHARE
           BASIC                                 $         .06     $         .31     $        1.03      $         .91
           DILUTED                               $         .05     $         .28     $         .98      $         .83

     WEIGHTED AVERAGE SHARES OUTSTANDING
           BASIC                                    12,120,732         7,437,078        12,117,361          7,414,584
           DILUTED                                  12,488,387         8,150,277        12,747,779          8,059,785


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

                                       4


                              DIANON SYSTEMS, INC.
                 CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY

              FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2002 AND 2001
                                   (UNAUDITED)



                                                                                                 Accumulated
                                                                        Common Stock              Additional          Other
                                                               ------------------------------       Paid-In       Comprehensive
                                                  Total           Shares            Amount          Capital           Income
                                              -------------    -------------    -------------    -------------    -------------
                                                                                                   
BALANCE, December 31, 2000                    $  52,258,738        7,397,323    $      73,974    $  35,877,828    $          --
     Net income                                   6,724,522               --               --               --               --
     Unrealized gain on securities                       --               --               --               --               --

     Comprehensive income                                --               --               --               --               --

     Stock options exercised                        439,565           58,235              582          438,983               --
     Tax effect for stock options exercised         670,921               --               --          670,921               --
     Employee stock purchase plan /  other           99,746               --               --           75,795               --
     Stock grants                                    31,662              850                8           31,654               --
                                              -------------    -------------    -------------    -------------    -------------
BALANCE, September 30, 2001                   $  60,225,154        7,456,408    $      74,564    $  37,095,181    $          --
                                              =============    =============    =============    =============    =============

BALANCE, December 31, 2001                    $ 265,636,283       11,896,140    $     118,961    $ 242,987,849    $          --
     Net income                                  12,444,036               --               --               --               --
     Unrealized gain on securities                  792,040               --               --               --          792,040

     Comprehensive income                                --               --               --               --               --

     Stock options exercised                      5,845,522          458,938            4,590        5,840,932               --
     Tax effect for stock options                 7,693,147               --               --        7,693,147               --
     exercised
     Return of common stock held in escrow         (113,825)          (3,066)             (31)        (113,794)              --
     Employee stock purchase plan / other           164,561               --               --          131,375               --
     Common stock acquired for treasury         (10,106,289)              --               --               --               --
                                              -------------    -------------    -------------    -------------    -------------
BALANCE, September 30, 2002                   $ 282,355,475       12,352,012    $     123,520    $ 256,539,509    $     792,040
                                              =============    =============    =============    =============    =============


                                                                     Common Stock
                                                                 Acquired for Treasury
                                                 Retained     ------------------------------    Comprehensive
                                                 Earnings         Shares           Amount           Income
                                              -------------   -------------    -------------    -------------
                                                                      
BALANCE, December 31, 2000                    $  16,427,788         (12,620)   $    (120,852)
     Net income                                   6,724,522              --               --    $   6,724,522
     Unrealized gain on securities                       --              --               --               --
                                                                                                -------------
     Comprehensive income                                --              --               --    $   6,724,522
                                                                                                =============
     Stock options exercised                             --              --               --
     Tax effect for stock options exercised              --              --               --
     Employee stock purchase plan /  other               --           2,501           23,951
     Stock grants                                        --              --               --
                                              -------------   -------------    -------------
BALANCE, September 30, 2001                   $  23,152,310         (10,119)   $     (96,901)
                                              =============   =============    =============

BALANCE, December 31, 2001                    $  22,620,561          (9,511)   $     (91,088)
     Net income                                  12,444,036              --               --    $  12,444,036
     Unrealized gain on securities                       --              --               --          792,040
                                                                                                -------------
     Comprehensive income                                --              --               --    $  13,236,076
                                                                                                =============
     Stock options exercised                             --              --               --
     Tax effect for stock options                        --              --               --
     exercised
     Return of common stock held in escrow               --              --               --
     Employee stock purchase plan / other                --           3,465           33,186
     Common stock acquired for treasury                  --        (288,243)     (10,106,289)
                                              -------------   -------------    -------------
BALANCE, September 30, 2002                   $  35,064,597        (294,289)   $ (10,164,191)
                                              =============   =============    =============


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

                                       5


                              DIANON SYSTEMS, INC.
                      CONSOLIDATED STATEMENTS OF CASH FLOWS

              FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2002 AND 2001
                                   (UNAUDITED)



                                                                                   SEPTEMBER 30,
                                                                              2002              2001
                                                                          ------------      ------------
                                                                                      
CASH FLOWS FROM OPERATING ACTIVITIES:
    Net income                                                            $ 12,444,036      $  6,724,522
Adjustments to reconcile net income to net
    cash provided by operations -
     Non-cash charges

         Depreciation and amortization                                       4,396,871         3,354,747
         Provision for bad debts                                                89,043                --
         Tax effect of stock options exercised                               7,693,147           670,921
         Deferred tax provision                                              3,723,527                --
         Stock compensation expense                                                 --            31,662
         Bond premium amortization                                             155,249                --
         Loss (gain) on disposal of fixed assets                                28,688           (24,077)
Changes in other current assets and liabilities
     Accounts receivable                                                    (8,314,004)          434,668
     Prepaid / refundable income taxes                                       2,924,475         2,245,894
     Prepaid expenses and other current assets                                 661,814          (470,697)
     Inventory                                                                (256,329)          (18,298)
     Other assets and other                                                    (76,655)         (159,704)
     Accounts payable and other accrued liabilities                          1,265,665         1,405,195
                                                                          ------------      ------------
                   Net cash provided by operating activities                24,735,527        14,194,833
                                                                          ------------      ------------

CASH FLOWS FROM INVESTING ACTIVITIES:
     Capital expenditures                                                   (2,645,640)       (1,575,284)
     Purchases of available-for-sale securities                            (50,192,527)               --
     Redemption of available-for-sale securities                             1,781,147                --
     Investment and acquisition of marketing rights                         (1,500,000)               --
     Acquisition of UroCor, Inc., net                                            4,389                --
     Proceeds from the sale of fixed assets                                     52,849            53,758
                                                                          ------------      ------------
                   Net cash used in investing activities                   (52,499,782)       (1,521,526)
                                                                          ------------      ------------

CASH FLOWS FROM FINANCING ACTIVITIES:
     Repayments of note payable                                                     --        (2,500,000)
     Purchase of common stock acquired for treasury                        (10,106,289)               --
     Employee stock purchase plan / other                                      164,561            99,746
     Exercise of stock options                                               5,845,522           439,565
     Repayments of capitalized lease obligations                              (484,666)          (47,238)
                                                                          ------------      ------------
                 Net cash used in financing activities                      (4,580,872)       (2,007,927)
                                                                          ------------      ------------


                 Net (decrease) increase in cash and cash equivalents      (32,345,127)       10,665,380

CASH AND CASH EQUIVALENTS, beginning of period                              41,229,353        12,515,424
                                                                          ------------      ------------
CASH AND CASH EQUIVALENTS, end of period                                  $  8,884,226      $ 23,180,804
                                                                          ============      ============

SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
     Cash paid during the period:
         Interest                                                         $     17,132      $     62,758
         Income taxes paid, net of refunds                                     170,192         2,160,696


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

                                       6


                              DIANON SYSTEMS, INC.
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1.       The Company - The consolidated financial statements as of and for the
         three months and nine months ended September 30, 2002 and 2001 have
         been prepared by DIANON Systems, Inc. ("Dianon" or the "Company")
         without audit. In the opinion of management, all adjustments necessary
         to present fairly the financial position, results of operations and
         cash flows for such periods have been made, and the interim accounting
         policies followed are in conformity with accounting principles
         generally accepted in the United States and are consistent with those
         applied for annual periods as described in Dianon's annual report for
         the year ended December 31, 2001, previously filed on Form 10-K and
         10-K/A with the Securities and Exchange Commission (the "Annual
         Report").

         Certain information and note disclosures normally included in financial
         statements prepared in accordance with accounting principles generally
         accepted in the United States have been omitted. It is suggested that
         these consolidated financial statements be read in conjunction with the
         financial statements included in Dianon's Annual Report for the year
         ended December 31, 2001. The results of operations for the three months
         and nine months ended September 30, 2002 and 2001 are not necessarily
         indicative of the operating results for the full years.

         Acquisitions - In the second quarter of 2002, 3,066 shares of the
         Company's common stock were distributed to the Company from the escrow
         account established in connection with the Company's acquisition in
         October 2000 of John H. Altshuler, M.D., P.C., a pathology practice
         located in Englewood, Colorado. In the second quarter of 2002 the
         Company also accelerated the amortization of the customer list related
         to the Altshuler acquisition by approximately $205,000 to reflect the
         remaining useful life.

         In the second quarter of 2002, the Company reversed approximately
         $711,000 of allowance for bad debts. This was the portion of the $5.5
         million special bad debt provision that the Company recorded in the
         fourth quarter of 2001 relating to the acquisition in November 2001 of
         UroCor, Inc. ("UroCor") that was determined to be no longer required.

         Pro forma historical results (unaudited) for the three month and nine
         month periods ended September 30, 2001, adjusted as if UroCor had been
         acquired on January 1, 2001, approximates $43.1 million and $129.9
         million in revenue, respectively, $2.9 million and $11.9 million in net
         income, respectively, and $0.24 and $0.98 in diluted earnings per
         share, respectively. The $11.9 million pro forma net income for the
         nine months ended September 30, 2001, stated above, includes a
         one-time, special credit for bad debts of $4.6 million (or $0.38
         diluted earnings per share) recorded by UroCor. The pro forma results
         are not necessarily indicative of what actually would have occurred if
         the acquisition had been completed as of January 1, 2001, nor are they
         necessarily indicative of future results.

         In the first quarter of 2002, the Company paid MDdatacor, Inc.
         ("MDdatacor") $1.0 million for the exclusive marketing rights for a
         medical records search tool for urology and gastroenterology physician
         practice group customers. The Company also acquired a 13.7% interest in
         MDdatacor. The Company allocated the total investment in MDdatacor to
         the marketing rights ($750,000) and equity ($250,000) based on
         management's estimates of fair value. In the third quarter of 2002, the
         Company contributed an additional $500,000 to MDdatacor, increasing the
         Company's investment in MDdatacor to 16.6% as of September 30, 2002.
         The Company allocated the additional investment to the marketing rights
         ($375,000) and equity ($125,000) based on management's estimates of
         fair value.

                                       7


2.       Recent Accounting Pronouncements - In June 2001, the Financial
         Accounting Standards Board issued Statement of Financial Accounting
         Standards ("SFAS") No. 141, "Business Combinations," and SFAS No. 142,
         "Goodwill and Other Intangible Assets." SFAS No. 141 requires that all
         business combinations initiated after June 30, 2001 be accounted for
         using the purchase method, thus eliminating the use of the
         pooling-of-interests accounting for business combinations. SFAS No. 142
         revises the accounting for goodwill to eliminate amortization of
         goodwill after December 31, 2001. The statement requires an annual
         assessment of goodwill for impairment and more frequent assessments if
         circumstances indicate a possible impairment. In the second quarter of
         2002, the Company completed the initial test for impairment and
         determined that no goodwill impairment had occurred. The following
         table provides a reconciliation for the prior year's reported net
         income to adjusted net income had SFAS No. 142 been applied as of the
         beginning of fiscal 2001 for the three month and nine month periods
         ended September 30, 2001.



                                               For the three months ended                For the nine months ended
                                                   September 30, 2001                       September 30, 2001
                                         --------------------------------------     -----------------------------------
                                            Income        Basic       Diluted          Income        Basic     Diluted
                                         available to    Earnings    Earnings       available to   Earnings   Earnings
                                            common         per          per            common         per        per
                                         stockholders      share       share        stockholders     share      share
                                         -------------  ----------  -----------     -------------  ---------  ---------
                                                                                            
         Reported net income
         attributed to DIANON common
         stock                           $   2,307,427  $     0.31  $      0.28     $   6,724,522  $    0.91  $    0.83

         Add back amortization of
         goodwill, net of income tax            27,702        0.00         0.00            83,106       0.01       0.01
                                         -------------  ----------  -----------     -------------  ---------  ---------

         Adjusted net income
         attributed to DIANON common
         stock                           $   2,335,129  $     0.31  $      0.28     $   6,807,628  $    0.92  $    0.84
                                         =============  ==========  ===========     =============  =========  =========


         In August 2001, the Financial Accounting Standards Board issued SFAS
         No. 143, "Accounting for Asset Retirement Obligations," which is
         effective in 2003. It requires the recording of an asset equal to the
         present value of the estimated costs associated with the retirement of
         long-lived assets where a legal or contractual obligation exists. The
         asset is required to be depreciated over the life of the related
         equipment or facility, and the liability accreted each year based on a
         present value interest rate. The Company does not believe that the
         adoption of SFAS No. 143 will have a material impact on its financial
         position or results of operations.

         In October 2001, the Financial Accounting Standards Board issued SFAS
         No. 144, "Accounting for the Impairment or Disposal of Long-Lived
         Assets." SFAS No. 144 supersedes SFAS No. 121, "Accounting for the
         Impairment of Long-Lived Assets and for Long-Lived Assets to be
         Disposed of." It establishes a single accounting model for the
         impairment of long-lived assets to be held and used or to be disposed
         of by sale or abandonment and broadens the definition of discontinued
         operations. The provisions of this statement are effective for
         financial statements issued for fiscal years beginning after December
         15, 2001. The adoption of SFAS No. 144 did not have a material impact
         on the Company's financial position or results of operations.

         In June 2002, the Financial Accounting Standards Board issued SFAS No.
         146, "Accounting for Costs Associated with Exit or Disposal
         Activities." SFAS No. 146 nullifies Emerging Issues Task Force (EITF)
         Issue No. 94-3, "Liability Recognition for Certain Employee Termination
         Benefits and Other Costs to Exit an Activity (including Certain Costs
         Incurred in a Restructuring)." This statement requires that a liability
         for a cost associated with an exit or disposal activity be recognized
         when the liability is incurred. Under EITF Issue No. 94-3, a liability
         for an exit cost was recognized at the date of the entity committed to
         an exit plan. The provisions of this statement are effective for exit
         or disposal activities that are initiated after December 31, 2002, with
         early application encouraged. The Company does not believe that the
         adoption of SFAS No. 146 will have a material impact on its financial
         position or results of operations.

                                       8


3.       Earnings per share - Basic earnings per share have been computed based
         on the weighted average number of common shares outstanding during each
         period. Diluted earnings per share have been computed based on the
         weighted average number of common shares and common equivalent shares
         outstanding during each period. Common equivalent shares outstanding
         include the common equivalent shares calculated for warrants and stock
         options under the treasury stock method. Below is a reconciliation of
         the numerators and denominators of the basic and diluted earnings per
         share computations for the three month and nine month periods ended
         September 30, 2002 and 2001.



                                             Three months ended                Nine months ended
                                               September 30,                     September 30,
                                            2002          2001                2002           2001
                                        -----------------------------    -------------------------------
                                                                              
       BASIC EARNING PER SHARE:
       Weighted-average number of
       common shares outstanding          12,120,732       7,437,078         12,117,361       7,414,584

       DILUTIVE EFFECT OF:

       Stock options                         367,655         713,199            630,418         645,201
                                        -----------------------------    -------------------------------

       DILUTED EARNINGS PER SHARE:
       Weighted-average number of
       common shares outstanding          12,488,387       8,150,277         12,747,779       8,059,785
                                        =============================    ===============================

       NET INCOME                           $673,317      $2,307,427        $12,444,036      $6,724,522
                                        =============================    ===============================

       BASIC EARNINGS PER SHARE                $0.06           $0.31              $1.03           $0.91
                                        =============================    ===============================

       DILUTED EARNINGS PER SHARE              $0.05           $0.28              $0.98           $0.83
                                        =============================    ===============================


    For the three and nine months ended September 30, 2002, outstanding options
    to purchase 563,447 and 18,250, respectively, shares of common stock, at
    prices ranging from $39.80 to $63.59 and $56.70 to $63.59, respectively, per
    share, were not included in the computation of diluted earnings per share
    because the exercise price of the options was greater than the average
    market price of common shares.

    For the nine months ended September 30, 2001, outstanding options to
    purchase 18,912 shares of common stock, at prices ranging from $40.06 to
    $45.50 per share, were not included in the computation of diluted earnings
    per share because the exercise price of the options was greater than the
    average market price of common shares. There were no options outstanding
    that were not included in the computation of diluted earnings per share for
    the three months ended September 30, 2001.

                                       9


4.       Investment Securities - As of September 30, 2002, the Company had
         investment securities of $51.2 million. The portfolio consisted
         primarily of U.S. Government agency securities with maturities of less
         than three years. The Company has evaluated its investment policies
         consistent with SFAS No. 115, "Accounting for Certain Investments in
         Debt and Equity Securities," and determined that all of its investment
         securities are to be classified as available-for-sale.
         Available-for-sale securities are carried at fair value, with the
         unrealized gains and losses reported in Stockholders' Equity under the
         caption "Accumulated Other Comprehensive Income." The Company views its
         available-for-sales securities as available to support its current
         operations and to fund the Company's stock repurchase program and,
         accordingly, classifies them as current assets on the balance sheet.
         The amortized cost of debt securities is adjusted for amortization of
         premiums and accretion of discounts to maturity. Such amortization is
         included in interest income, net. The cost of securities sold is based
         on the specific identification method. Interest on available-for-sale
         securities is included in interest income.

         The following is a summary of investment securities classified as
         "available-for-sale" securities as required by SFAS 115 as of September
         30, 2002 and December 31, 2001:

                                               September 30,    December 31,
                                                   2002            2001
                                                -----------     -----------
                 Debt investments:

                     Cost                       $49,991,349     $ 1,071,778
                     Gross unrealized gains       1,175,910              --
                                                -----------     -----------
                 Estimated fair value           $51,167,259     $ 1,071,778
                                                ===========     ===========


5.       Legal Proceedings - The Company received a subpoena dated November 16,
         2000, issued by the United States Attorney's Office for Connecticut,
         requesting the production of a variety of documents, with a particular
         focus on documents relating to billing for tumor biomarkers, DNA
         testing and screening tests. In the third quarter of 2002, the Company
         recorded a special charge of $5.5 million to cover the anticipated
         payment to be made to the government relating to the Department of
         Justice ("D.O.J.") investigation discussed above. This amount includes
         related legal costs. Although a final settlement has not yet been
         reached, the Company, believes, based on recent discussions with
         outside legal counsel and the government, the payment is probable and
         reasonably estimable.

         As part of the acquisitionof UroCor in November 2001, the Company
         assumed responsibility and liability for certain pre-acquisition
         contingencies including expenses relating to the previously announced
         UroCor D.O.J. investigation, compliance with the UroCor corporate
         integrity agreement and potential indemnification of legal and other
         fees and costs for former directors, officers and employees of UroCor
         in connection with any criminal investigation related to the UroCor
         D.O.J. settlement. In connection with the preliminary Urocor purchase
         price allocation in 2001, the Company estimated the probable
         indemnification expenses to be $1.0 million, but there is no assurance
         that this amount will not increase significantly.

         The Company is involved in certain other legal matters, including
         professional liability claims, which periodically arise in the normal
         course of business. Management believes that the outcome of these legal
         matters will not have a material adverse effect on the financial
         position and results of operations of the Company. Furthermore,
         management believes the Company maintains adequate insurance coverage
         or has established adequate reserves for known contingencies.

6.       Income Taxes - During the third quarter of 2002, the Company's
         effective tax rate increased from 40.5% to 85%. The increase is because
         the Company did not record an income tax benefit related to a portion
         of the $5.5 million special charge discussed in Note 5, as the Company
         cannot presently determine whether the amounts to be paid to the
         government will be deductible for income tax purposes.

                                       10


Item 2.         MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS
         THREE MONTHS AND NINE MONTHS ENDED SEPTEMBER 30, 2002 AND 2001
                                   (UNAUDITED)

The descriptive analysis contained herein compares the financial results of the
three months and nine months ended September 30, 2002 ("Third Quarter-2002" and
"Nine Months-2002", respectively) to the three months and nine months ended
September 30, 2001 ("Third Quarter-2001" and "Nine Months-2001", respectively).

RESULTS OF OPERATIONS
- ---------------------

     o   NET REVENUES

Net revenues increased 63% to $47.1 million in the Third Quarter-2002 from $28.9
million in the Third Quarter-2001, and 67% to $141.0 million in the Nine
Months-2002 from $84.5 million in the Nine Months-2001. This increase reflects
the acquisition of UroCor as well as the effects of strong volume gains in
pathology and genetics testing and a favorable reimbursement climate for some of
the Company's most commonly performed tests. Our Oklahoma facility (formerly
UroCor) generated approximately $10.9 million in revenues in the Third
Quarter-2002 and $34.2 million in revenues in the Nine Months-2002.

Anatomic pathology services involve the preparation and pathologic
interpretation of tissue from biopsy specimens for the diagnosis of cancer and
other significant diseases. Anatomic pathology net revenues increased to $32.2
million in the Third Quarter-2002 from $20.0 million in the Third Quarter-2001,
representing a 61% increase, and increased to $98.1 million in the Nine
Months-2002 from $58.3 million in the Nine Months-2001, representing a 68%
increase. The revenue growth reflects the UroCor acquisition, as well as
increased market penetration in the anatomic pathology area.

Genetics services consists primarily of cytogenetics, fluorescent in situ
hybridization, and molecular analysis primarily for leukemias, lymphomas,
infectious disease and inherited disorders. Genetics net revenues increased to
$6.3 million in the Third Quarter-2002 from $4.9 million in the Third
Quarter-2001, representing a 28% increase, and increased to $18.0 million in the
Nine Months-2002 from $14.3 million in the Nine Months-2001, representing a 26%
increase. The revenue growth reflects increased market penetration.

Clinical chemistry testing consists of tumor markers, cultures, specialized
urine testing and routine tests for general health conditions. Clinical
chemistry net revenues increased to $8.6 million in the Third Quarter-2002 from
$4.0 million in the Third Quarter-2001, representing a 113% increase, and
increased to $24.8 million in the Nine Months-2002 from $11.9 million in the
Nine Months-2001, representing a 108% increase. This increase is primarily
related to the UroCor acquisition.

The clinical laboratory industry, which includes both clinical chemistry and
anatomic pathology, has seen steady and continuing downward pressure on prices
exerted by both government and private third-party payers. Payment for services
such as those provided by Dianon is and will likely continue to be affected by
periodic reevaluations made by payers concerning the level of reimbursement for
services provided by Dianon. Over time, Congress has reduced the national cap on
Medicare laboratory fee schedules (under which Dianon's clinical chemistry
services are reimbursed) to 74% of the national median. In addition, the
Balanced Budget Act of 1997 ("BBA") freezes fee schedule payments (i.e., no
increases or decreases) for the 1998-2002 period.

The clinical laboratory industry has also recently experienced increases in the
payment rate for certain tests, including some of those performed by the
Company. Beginning in 1998, Medicare began covering screening pap smears for
certain Medicare beneficiaries, and the Balanced Budget Refinement Act of 1999
("BBRA") required the Secretary of the Department of Health and Human Services
to establish a national minimum payment amount equal to $14.60 for diagnostic or
screening pap smear laboratory tests furnished on or after January 1, 2000.
Previously, the national payment cap for a pap smear was approximately $7.15.
The BBRA also encouraged the Centers for Medicare and Medicaid Services ("CMS")
(formerly known as the Health Care Financing Administration or "HCFA") to
institute an appropriate increase in the payment rate for new cervical cancer
screening technologies, such as the technologies used by Dianon, that have been
approved by the FDA as significantly more effective than a conventional pap
smear. In March 2001, CMS established a national limit of $28 for the new pap
smear technologies used by Dianon, which is nearly twice the level of
reimbursement for the conventional pap smear. Payments in states in which Dianon
has laboratories that furnish the new pap smear tests range from $27.90 to
$28.00. The Medicare, Medicaid, and SCHIP ("State Children's Health Insurance
Program") Benefits Improvement and Protection Act of 2000 ("BIPA"), signed into
law on December 21, 2000, requires that the national limitation amount for new
lab tests equal 100% of the national median for such tests (versus the 74%
applied to other tests). In addition, BIPA included a provision to change the
frequency of covered screening pap smears from at least every three years to at
least every two years. The addition of Medicare coverage for more frequent pap
smear tests and higher reimbursement for certain types of pap smear tests have
provided and are expected to continue to provide additional revenues for Dianon.

                                       11


With respect to Dianon's anatomic pathology services, which are reimbursed under
the Medicare physician fee schedule rather than the Medicare laboratory fee
schedule, Medicare reimbursement amounts generally declined with the
implementation of the resource-based relative value scale ("RBRVS") system,
which went into effect in 1992 and was fully phased in by the end of 1996. Under
this system, relative value units ("RVUs") are established for the physician
work, practice expense and malpractice expense involved with each physician
service. Of these three, however, the physician work and practice expense
components comprise the vast majority of the value of a service. The RVUs for a
service may be changed from time to time, and once the RVUs are finalized each
year, they are multiplied by a "conversion factor" in order to calculate the
actual payment for a service. The conversion factor is a monetary amount that
changes from year to year based on a variety of factors, including changes in
health-related and overall economic indicators. Generally, anatomic pathology
reimbursement rates declined during the fee schedule phase-in period, despite an
increase in payment rates for certain pathology services performed by Dianon.
Due to a five-year review, in 1997 there was an overall decrease in the
physician work RVUs established for pathology services. Another five-year review
of the work value component was completed in 2001, published in the Federal
Register on June 8, 2001, and went into effect on January 1, 2002. The changes
recommended as a result of this more recent review are not expected to have any
significant effect on payment for pathology services.

In the final 2002 Medicare physician fee schedule, published in November 2001,
CMS estimated that refinements and changes in the RVUs for physician work and
practice expense would result in a 3% increase in payments for pathology
services in 2002, compared to what would have occurred in 2002 had the rule not
been published. This estimate is primarily due to the use of new data to
calculate the practice expense component of the RVUs. However, due to budget
neutrality requirements and other economic factors, the conversion factor used
to calculate the fee schedule payments was reduced approximately 5.4% in 2002,
which offset some of the expected increase in payments for pathology services.
However, for Dianon's most frequently billed service, the 88305 surgical biopsy,
reimbursement from Medicare increased approximately 5.5%.

As a result of Congress' concerns about the significant decrease in the
conversion factor in 2002, and anticipating further decreases in future years,
legislation has been passed by the House of Representatives that would require a
conversion factor increase of 6% over the next three years, and make changes in
the way the conversion factor is calculated in future years. The Senate is also
considering similar legislation. It is not yet known whether this, or similar,
legislation will be passed by Congress and signed into law before the 2003 fee
schedule goes into effect on January 1, 2003.

On June 28, 2002, the proposed 2003 Medicare physician fee schedule was
published. The proposed changes, if finalized, could result in significant
decreases in Medicare reimbursement for some of the pathology services most
frequently billed by Dianon. These decreases would be the result of both a
decrease in the conversion factor, based on the current methodology for updating
it, and on proposed changes in the data and methodology used to calculate the
RVUs for certain pathology services. As noted above, the House of
Representatives has approved legislation that would require an increase in the
conversion factor in each of the next three years, and similar legislation has
been introduced in the Senate. CMS accepted comments on the proposed 2003
physician fee schedule, and the final rule was expected be published at the
beginning of November 2002, but was delayed due to incomplete data used to
establish the RVUs for certain physician services, according to CMS. Therefore,
it is not yet known whether the changes proposed by CMS will be implemented, or
what the final effect such changes, and any changes in the conversion factor,
will have on reimbursement for the pathology services provided by Dianon.
However, the outcome could have a material adverse effect on the Company's
revenues.

The BBA also required the Secretary of the Department of Health and Human
Services to use a negotiated rulemaking process to adopt uniform coverage,
administration and payment policies for lab tests. The final rule was published
on November 23, 2001. This rule establishes national coverage policies for many
of the most commonly ordered lab tests, thereby replacing local Medicare
policies, which sometimes varied, and it establishes other uniform requirements
related to submission of claims for lab tests. Although most of the provisions
of the rule went into effect only very recently, the Company believes that the
new rule will level the playing field and result in more consistent
reimbursement among providers of laboratory testing services.

                                       12


CMS had announced that effective January 1, 2001, independent labs would no
longer be allowed to bill Medicare for the technical component ("TC") of
pathology services furnished to Medicare beneficiaries who are hospital
inpatients. Independent labs would still be able to bill and be paid for the TC
of pathology services provided to beneficiaries who are in non-hospital
settings, but for the TC of services provided to a hospital inpatient, the
independent lab would have to make arrangements with the hospital in order to
receive payment. Also beginning on January 1, 2001, under new regulations for
hospital outpatient reimbursement, independent labs would be limited to billing
the hospital for the TC of any pathology services furnished to hospital
outpatients. In other words, under the regulation, independent laboratories that
perform the technical component of pathology services for hospital outpatient
services would no longer be allowed to bill Medicare for these services and
must, instead, bill the hospital. However, BIPA included a "grand fathering"
provision allowing independent labs to continue to bill and be paid for the TC
of services provided to both hospital inpatients and outpatients for an
additional two years, until January 2003. Legislation to further extend this
deadline has been introduced in Congress. Since Dianon does only minimal testing
for hospital inpatients and outpatients, these changes are not expected to have
a material financial impact on Dianon.

The BBA contained measures to establish market-oriented purchasing for Medicare,
including prospective payment systems ("PPS") for hospital outpatient services,
home health care, and nursing home care. All of these systems have now been
implemented. Since Dianon does only minimal clinical laboratory testing for
hospital outpatient, home health care and nursing facility patients, these
changes have not had a material financial impact on Dianon.

Dianon's Form 10-K and 10-K/A for the year ended December 31, 2001, previously
filed with the Securities and Exchange Commission, contain additional
information regarding the complex area of reimbursement.

     o   COST OF SALES

Cost of sales, which consists primarily of payroll, laboratory supplies, outside
laboratory services, logistics and depreciation expense, increased to $23.4
million in the Third Quarter-2002 from $16.1 million in the Third Quarter-2001,
and to $70.2 million for the Nine Months-2002 from $46.9 million for the Nine
Months-2001. As a percentage of revenues, cost of sales improved to 50% in the
Third Quarter-2002 from 56% in the Third Quarter-2001, as well as improving to
50% in the Nine Months-2002 from 56% in the Nine Months-2001. These improvements
are a result of cost control initiatives and to the effective management of
semi-variable and fixed costs such as, laboratory technician salaries and
instrumentation expenses, respectively.

     o   GROSS PROFIT

Gross profit totaled $23.7 million in the Third Quarter-2002 versus $12.8
million in the Third Quarter-2001, reflecting a gross profit margin of 50% and
44%, respectively. Gross profit for the Nine Months-2002 totaled $70.7 million
versus $37.6 million in the prior year, representing margins of 50% and 44%,
respectively. The increases in gross profits are a result of increased revenues,
cost control initiatives, favorable product line mix and the effective
management of semi-variable and fixed costs such as, laboratory technician
salaries and instrumentation expenses, respectively.

     o   SELLING, GENERAL AND ADMINISTRATIVE EXPENSES

Selling, general and administrative expenses increased to $13.5 million in the
Third Quarter-2002 from $8.5 million in the Third Quarter-2001, and to $40.4
million for the Nine Months-2002 from $24.8 million for the Nine Months-2001.
These increases are primarily the result of the acquisition of UroCor as well as
increased insurance premiums and commission expense associated with increased
revenues. As a percentage of sales, SG&A expenses decreased to 29% from 30% for
the Third Quarter-2002 and the Third Quarter-2001, respectively, and remained
constant at 29% for both the Nine Months-2002 and Nine Months-2001.

     o   SPECIAL CREDIT FOR BAD DEBTS

In the second quarter of 2002, the Company reversed approximately $711,000 of
allowance for bad debts. This was the portion of the $5.5 million special bad
debt provision that the Company recorded in the fourth quarter of 2001 relating
to the acquisition in November 2001 of UroCor, Inc. ("UroCor") that was
determined to be no longer required.

                                       13


     o   SPECIAL CHARGE

In the third quarter of 2002, the Company recorded a special charge of $5.5
million to cover the anticipated payment to be made to the government relating
to the Department of Justice ("D.O.J.") investigation discussed above. This
amount includes related legal costs. Although a final settlement has not yet
been reached, the Company, believes, based on recent discussions with outside
legal counsel and the government, the payment is probable and reasonably
estimable.

     o   AMORTIZATION OF INTANGIBLE ASSETS

Amortization of intangible assets increased to $640,000 in the Third
Quarter-2002 from $339,000 in the Third Quarter-2001, and to $1.5 million in the
Nine Months-2002 from $1.0 million in the Nine Months-2001. These increases for
both the Third Quarter-2002 and the Nine Months-2002 are primarily a result of
the amortization of the UroCor customer list, the marketing rights from
MDdatacor and the accelerated amortization of the Colorado facility customer
list, partially offset by the reversal of amortization in connection with the
return of 3,066 shares of the Company's common stock relating to the
finalization of the John H. Altshuler, M.D., P.C. acquisition Escrow Agreement
dated October 2, 2000 as well as the Response Genetics amortization that was
fully amortized as of December 31, 2001 and therefore no longer being amortized
in 2002.

     o   RESEARCH AND DEVELOPMENT EXPENSES

Research and development expenses slightly decreased to $271,000 in the Third
Quarter-2002 from $287,000 in the Third Quarter-2001, and remained constant at
$1.0 million for both the Nine Months-2002 and the Nine Months-2001. Research
and development expenses consist primarily of CarePath(TM) services, a
proprietary disease management system designed for patients, physicians and
managed care organizations. CarePath(TM) services include material for patients
to better understand their pathology results, aggregate data on pathology for
physician practices and information to assist health plans in managing patients
with significant diseases diagnosed by the Company.

     o   INCOME FROM OPERATIONS

Income from operations increased to $3.9 million in the Third Quarter-2002 from
$3.7 million in the Third Quarter-2001, and to $23.0 million from $10.8 million
for the Nine Months-2002 and the Nine Months-2001, respectively. These increases
reflect the effects of the Urocor acquisition offset by the $5.5 million special
charge relating to the D.O.J. investigation in the third quarter 2002 and
include $711,000 special credit for bad debts recorded in the second quarter of
2002.

Income from operations, before the $5.5 million special charge relating to the
D.O.J. investigation, increased to $9.3 million in the Third Quarter-2002 from
$3.7 million in the Third Quarter-2001. Income from operations for the Nine
Months-2002 and the Nine Months-2001, before both the $5.5 million special
charge relating to the D.O.J. investigation and the $711,000 special credit for
bad debts recorded in the second quarter of 2002, increased to $27.8 million
from $10.8 million, respectively. These increases are a result of increased
revenues, cost control initiatives and the effective management of semi-variable
and fixed costs.

EBITDA is defined as income before interest expense, income tax expense and
depreciation and amortization. Adjusted EBITDA excludes the non-recurring $5.5
million special charge relating to the D.O.J. investigation and the $711,000
special credit for bad debts. These items are excluded from Adjusted EBITDA as
these items do not impact operating results on a recurring basis. Management
considers EBITDA to be one measure of the cash flows from operations of Dianon
before debt service that provides a relevant basis for comparison, and Adjusted
EBITDA is presented to assist investors in analyzing the performance of Dianon.
This information should not be considered as an alternative to any measure of
performance as promulgated under accounting principles generally accepted in the
United States, nor should it be considered as an indicator of the overall
financial performance of Dianon. Dianon's calculations of EBITDA and Adjusted
EBITDA may be different from the calculations used by other companies and,
therefore, comparability may be limited.

                                       14


EBITDA and Adjusted EBITDA for the third quarter and nine months ended 2002 and
2001 are as follows:



                                                               Third Quarter                  Nine Months Ended
                                                               -------------                  -----------------
                                                           2002            2001             2002            2001
                                                           ----            ----             ----            ----
                                                                                               
       EBITDA                                            $ 5,468,406       $4,693,950     $27,420,387      $14,199,315
       Adjusted EBITDA                                   $10,918,406       $4,693,950     $32,159,430      $14,199,315
       Adjusted EBITDA as a percentage of sales                23.2%            16.2%           22.8%            16.8%


     o   INTEREST INCOME, NET

Net interest income increased to $522,000 in the Third Quarter-2002 from
$184,000 in the Third Quarter-2001, and to $1.2 million in the Nine Months-2002
from $457,000 in the Nine Months-2001, due to investments in available-for-sale
securities that are yielding higher interest rates as well as higher cash
balances earning interest income.

     o   PROVISION FOR INCOME TAXES

The provision for income taxes includes an additional tax provision as all or
part of the anticipated payment to the government, related to the D.O.J.
investigation, may be deemed non-deductible for tax purposes. The provision,
before the additional amounts, reflects a 40.5% effective tax rate for both the
three month and nine month periods ended 2002 and 2001, totaling $3.7 million in
the Third Quarter-2002 and $1.6 million in the Third Quarter-2001 and $11.7
million in the Nine Months-2002 and $4.6 million in the Nine Months-2001.

     o   NET INCOME

Net income decreased 71% to $673,000 in the Third Quarter-2002 from $2.3 million
in the Third Quarter-2001, and increased 85% to $12.4 million in the Nine
Months-2002 from $6.7 million in the Nine Months-2001. Basic earnings per share
decreased 81% to $0.06 per share in the Third Quarter-2002 from $0.31 per share
in the Third Quarter-2001, and increased 13% to $1.03 per share in the Nine
Months-2002 from $0.91 per share in the Nine Months-2001, while diluted earnings
per share decreased 82% to $0.05 per share in the Third Quarter-2002 from $0.28
per share in the Third Quarter-2001, and increased 18% to $0.98 per share in the
Nine Months-2002 from $0.83 per share in the Nine Months-2001.

On a pro forma basis, before the $5.5 million ($5.2 million after tax) special
charge relating to the D.O.J. investigation and the $711,000 ($423,000 after
tax) special credit for bad debts recorded in the second quarter of 2002, net
income increased 154% to $5.9 million in the Third Quarter-2002 from $2.3
million in the Third Quarter-2001, and 156% to $17.2 million in the Nine
Months-2002 from $6.7 million in the Nine Months-2001. On a pro forma basis,
before the special charge relating to the D.O.J. investigation and the special
credit for bad debts, basic earnings per share increased 55% to $0.48 per share
in the Third Quarter-2002 from $0.31 per share in the Third Quarter-2001, and
56% to $1.42 per share in the Nine Months-2002 from $0.91 per share in the Nine
Months-2001, while diluted earnings per share increased 68% to $0.47 per share
in the Third Quarter-2002 from $0.28 per share in the Third Quarter-2001, and
63% to $1.35 per share in the Nine Months-2002 from $0.83 per share in the Nine
Months-2001.

                                       15


LIQUIDITY AND CAPITAL RESOURCES
- -------------------------------

At September 30, 2002, Dianon had total cash and cash equivalents and
available-for-sale securities of $60.1 million, comprising of $8.9 million in
cash and cash equivalents, substantially all of which was invested in a fund
holding U.S. Treasury securities with maturities of less than three months and
$51.2 million in available-for-sale securities, consisting of high grade, fixed
income securities with maturities of less than three years. Working capital was
$89.6 million and $68.8 million as of September 30, 2002 and December 31, 2001,
respectively, and the current ratios (current assets divided by current
liabilities) were 5.0:1 and 4.2:1, respectively.

Accounts receivable totaled $38.1 million as of September 30, 2002, representing
approximately 73 days of sales outstanding, compared to $29.9 million or 63 days
as of December 31, 2001. This increase is due to the UroCor acquisition as well
as the installation, during the third quarter, of the Company's laboratory
information system in the Oklahoma City facility, which required a temporary
interruption in claims processing to ensure the quality and integrity of data
transferred between the laboratory and billing system.

Capital expenditures for the Third Quarter-2002 and Nine Months-2002 totaled
approximately $562,000 and $2.6 million, respectively. Expenditures were
primarily related to building expansion, the new Port Washington, NY facility
and information system enhancements.

Dianon has a three-year, $15 million line of credit agreement with a bank which
expires in August 2003. The agreement includes various provisions regarding
borrowings under the facility, including financial and negative covenants. As of
September 30, 2002, no debt was outstanding on the line of credit and the
Company was compliant with all covenants.

In July 2002, Dianon's Board of Directors authorized the repurchase of an
additional $20.0 million of Dianon's Common Stock on the open market or in
private transactions, in addition to the previously approved amount of $12.0
million. As of September 30, 2002, Dianon had cumulatively repurchased
approximately 624,000 shares of Dianon's Common Stock for approximately $12.9
million leaving $19.1 million remaining for authorized repurchases under the
approved stock repurchase plans.

In July 2002, Dianon's shareholders approved an amendment to the Company's
Restated Certificate of Incorporation to increase the number of shares of
authorized Common Stock from 20,000,000 shares to 55,000,0000 shares. Such
additional shares may be issued in connection with capital raising efforts.

The Company's current medical malpractice insurance coverage expires as of
December 1, 2002. The Company expects that the renewal or replacement of its
medical malpractice insurance coverage for the next policy year will result in
significantly increased premium and deductible levels as a result of current
conditions in the insurance market for such coverage.

Dianon believes that cash flows from operations and available cash and cash
equivalents are adequate to fund Dianon's operations for the foreseeable future.

CRITICAL ACCOUNTING POLICIES
- ----------------------------

The Company's critical accounting policies and methods used in the preparation
of the Company's consolidated financial statements are described in Note 3 to
the Company's annual report on Form 10-K for the year ended December 31, 2001,
previously filed with the Securities and Exchange Commission. The following is a
brief discussion of the Company's more significant accounting policies and
methods.

Use of Estimates -

The preparation of financial statements in conformity with generally accepted
accounting principles requires management to make estimates and assumptions that
affect the reported amounts of assets and liabilities and the disclosure of
contingent assets and liabilities at the date of the financial statements and
the reported amounts of revenues and expenses during the reporting periods.
Actual amounts could differ significantly from these estimates.

                                       16


Revenue Recognition -

Revenues are recognized in the period in which services are provided. Revenues
subject to Medicare and Medicaid, direct physician and hospital billing are
based on fixed reimbursement fee schedules. All remaining revenues subject to
third-party reimbursement are recorded at the expected net realizable value.
Such estimates are revised periodically based upon the Company's actual
reimbursement experience.

Intangible Assets -

         Intangible assets are amortized on a straight-line basis over the
respective economic life as follows:

                                                     Years

                  Customer lists                     7 - 15
                  Tradename                          Indefinite

The Company periodically reviews the anticipated revenues related to intangible
assets to determine whether any adjustments to their carrying values are
necessary.

Income Taxes -

The Company utilizes the liability method of accounting for income taxes as set
forth in Statement of Financial Accounting Standards No. 109, "Accounting for
Income Taxes." Under this method, deferred income taxes are determined based on
the difference between the financial statement and tax basis of assets and
liabilities using presently enacted tax rates and regulations. The Company
records a valuation allowance against deferred tax assets when it is more likely
than not that the assets will not be realized.

RISK FACTORS; FORWARD-LOOKING STATEMENTS
- ----------------------------------------

This report contains forward-looking statements regarding Dianon's future plans,
objectives, and expected performance. These statements are based on assumptions
that Dianon believes are reasonable, but are subject to a wide range of risks
and uncertainties, and a number of factors could cause Dianon's actual results
to differ materially from those expressed in the forward-looking statements
referred to above. These factors include, among others, the uncertainties in
reimbursement rates and reimbursement coverage of various tests sold by Dianon
to beneficiaries of the Medicare and Medicaid programs; the possibility of being
deemed to be not in compliance with Federal or state regulatory requirements;
the uncertainties relating to the ability of Dianon to convince physicians
and/or managed care organizations to use Dianon as a provider of anatomic
pathology testing services; the ability of Dianon to maintain superior quality
relative to its competitors; the ability of Dianon to maintain its
hospital-based business in light of the competitive pressures and changes
occurring in hospital healthcare delivery; the uncertainties relating to states
erecting barriers to the performance of national anatomic laboratories, together
with the competitive pressures from small specialized laboratories and well
established local pathologists; and the uncertainties which would arise if
integrated delivery systems closed to outside providers emerged as the dominant
form of healthcare delivery.

We qualify any forward-looking statements entirely by these cautionary factors,
and readers are cautioned not to place undue reliance on forward-looking
statements.

The words "believe," "may," "will," "could," "should," "would," "anticipate,"
"estimate," "expect," "intend," "project," "objective," "seek," "strive,"
"might," "seeks," "likely result," "build," "grow," "plan," "goal," "expand,"
"position," or similar words, or the negatives of these words, or similar
terminology, identify forward-looking statements.

The forward-looking statements contained in this report only speak as of the
date of this report. The Company disclaims any obligation or undertaking to
provide any updates or revisions to any forward-looking statements to reflect
any change in management's expectations or any change in events, conditions or
circumstances on which the forward-looking statements are based.

                                       17


Item 3.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Pursuant to the Company's investment policy, idle and excess funds are invested
in high grade, fixed income securities generally for no more than three years
and are classified as available-for-sale. Investment securities as of September
30, 2002 consisted of debt securities primarily invested in U.S. Government
Agency Bullet Securities with maturities of less than three years. The Company
considers any net unrealized gain or loss on these investments to be temporary,
and reflects such gains or losses as a component of stockholders' equity.

Item 4.  CONTROLS AND PROCEDURES

Based on an evaluation of the disclosure controls and procedures conducted
within 90 days of the date of filing this report on Form 10-Q, the Chairman of
the Board and Chief Executive Officer, Kevin C. Johnson, and the Senior Vice
President, Finance and Chief Financial Officer, David R. Schreiber, have
concluded that the disclosure controls and procedures are effective.

There were no significant changes in our internal controls or in other factors
that could significantly affect those controls subsequent to the date of our
most recent evaluation thereof.

                                       18


PART II OTHER INFORMATION

Item 6    Exhibits and Reports on Form 8-K
          --------------------------------

          (a)      Exhibits:

11.1       Statement regarding computation of per share earnings is not required
           because the relevant computation can be determined from the material
           contained in the Financial Statements included herein.

99.1       Certification Pursuant to 18 U.S.C. Section 1350, as adopted pursuant
           to Section 906 of the Sarbanes-Oxley Act of 2002.

99.2       Certification Pursuant to 18 U.S.C. Section 1350, as adopted pursuant
           to Section 906 of the Sarbanes-Oxley Act of 2002.

           (b)     Reports on Form 8-K:


           During the period ending September 30, 2002, the Company filed the
           following current Reports on Form 8-K:

           (i)     Currrent Report on Form 8-K dated July 19, 2002, pertaining
                   to a proposed amendment to the Company's 2002 Stock Incentive
                   Plan.

           (ii)    Current Report on Form 8-K dated July 24, 2002, outlining the
                   proposed amendment to the Company's 2002 Stock Incentive
                   Plan.


                                       19



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.

                                         DIANON Systems, Inc.


                                         /s/ KEVIN C. JOHNSON
November 8, 2002                         ------------------------------------
                                         By: Kevin C. Johnson
                                             Chairman of the Board,
                                              President and Chief Executive
                                              Officer

                                             (Principal Executive Officer)


                                         /s/ DAVID R. SCHREIBER
November 8, 2002                         ------------------------------------
                                         By: David R. Schreiber
                                             Senior Vice President, Finance and
                                             Chief Financial Officer
                                             (Principal Financial Officer and
                                               Principal Accounting Officer)


                                       20


        CERTIFICATION PURSUANT TO RULE 13A-14 OR 15D-14 OF THE SECURITIES
         EXCHANGE ACT OF 1934, AS ADOPTED PURSUANT TO SECTION 302 OF THE
                           SARBANES-OXLEY ACT OF 2002

I, Kevin C. Johnson, certify that:

1.  I have reviewed this quarterly report on Form 10-Q of Dianon Systems, Inc.;

2. Based on my knowledge, this quarterly report does not contain any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this quarterly
report;

3. Based on my knowledge, the financial statements, and other financial
information included in this quarterly report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-14 and 15d-14) for the registrant and we have:

         a.       designed such disclosure controls and procedures to ensure
                  that material information relating to the registrant,
                  including its consolidated subsidiaries, is made known to us
                  by others within those entities, particularly during the
                  period in which this quarterly report is being prepared;

         b.       evaluated the effectiveness of the registrant's disclosure
                  controls and procedures as of a date within 90 days prior to
                  the filing date of this quarterly report (the "Evaluation
                  Date"); and

         c.       presented in this quarterly report our conclusions about the
                  effectiveness of the disclosure controls and procedures based
                  on our evaluation as of the Evaluation Date;

5. The registrant's other certifying officer and I have disclosed, based on our
most recent evaluation, to the registrant's auditors and the audit committee of
registrant's board of directors (or persons performing the equivalent function):

         a.       all significant deficiencies in the design or operation of
                  internal controls which could adversely affect the
                  registrant's ability to record, process, summarize and report
                  financial data and have identified for the registrant's
                  auditors any material weaknesses in internal controls; and

         b.       any fraud, whether or not material, that involves management
                  or other employees who have a significant role in the
                  registrant's internal controls; and

6. The registrant's other certifying officer and I have indicated in this
quarterly report whether or not there were significant changes in internal
controls or in other factors that could significantly affect internal controls
subsequent to the date of our most recent evaluation, including any corrective
actions with regard to significant deficiencies and material weaknesses.

Dated:  November 8, 2002

By:      /s/ Kevin C. Johnson
         ----------------------------
         Kevin C. Johnson
         Chief Executive Officer


        CERTIFICATION PURSUANT TO RULE 13A-14 OR 15D-14 OF THE SECURITIES
         EXCHANGE ACT OF 1934, AS ADOPTED PURSUANT TO SECTION 302 OF THE
                           SARBANES-OXLEY ACT OF 2002

I, David R. Schreiber, certify that:

1.  I have reviewed this quarterly report on Form 10-Q of Dianon Systems, Inc.;

2. Based on my knowledge, this quarterly report does not contain any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this quarterly
report;

3. Based on my knowledge, the financial statements, and other financial
information included in this quarterly report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this quarterly report;

4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-14 and 15d-14) for the registrant and we have:

         a.       designed such disclosure controls and procedures to ensure
                  that material information relating to the registrant,
                  including its consolidated subsidiaries, is made known to us
                  by others within those entities, particularly during the
                  period in which this quarterly report is being prepared;

         b.       evaluated the effectiveness of the registrant's disclosure
                  controls and procedures as of a date within 90 days prior to
                  the filing date of this quarterly report (the "Evaluation
                  Date"); and

         c.       presented in this quarterly report our conclusions about the
                  effectiveness of the disclosure controls and procedures based
                  on our evaluation as of the Evaluation Date;

5. The registrant's other certifying officer and I have disclosed, based on our
most recent evaluation, to the registrant's auditors and the audit committee of
registrant's board of directors (or persons performing the equivalent function):

         a.       all significant deficiencies in the design or operation of
                  internal controls which could adversely affect the
                  registrant's ability to record, process, summarize and report
                  financial data and have identified for the registrant's
                  auditors any material weaknesses in internal controls; and

         b.       any fraud, whether or not material, that involves management
                  or other employees who have a significant role in the
                  registrant's internal controls; and

6. The registrant's other certifying officer and I have indicated in this
quarterly report whether or not there were significant changes in internal
controls or in other factors that could significantly affect internal controls
subsequent to the date of our most recent evaluation, including any corrective
actions with regard to significant deficiencies and material weaknesses.

Dated: November 8, 2002

By:      /s/ David R. Schreiber
         ----------------------------
         David R. Schreiber
         Chief Financial Officer


                                  EXHIBIT INDEX

Exhibit      Description
- -------      -----------

11.1         Statement regarding computation of per share earnings is not
             required because the relevant computation can be determined from
             the material contained in the Financial Statements included herein.

99.1         Certification Pursuant to 18 U.S.C. Section 1350, as adopted
             pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

99.2         Certification Pursuant to 18 U.S.C. Section 1350, as adopted
             pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.