<ARTICLE> 5 <CIK> 0000779282 <NAME> DIANON SYSTEMS, INC. <MULTIPLIER> 1,000 <CURRENCY> U.S. Dollars <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-2000 <PERIOD-START> JAN-01-2000 <PERIOD-END> JUN-30-2000 <EXCHANGE-RATE> 1 <CASH> 11,102 <SECURITIES> 0 <RECEIVABLES> 22,006 <ALLOWANCES> 1,107 <INVENTORY> 1,454 <CURRENT-ASSETS> 35,050 <PP&E> 18,526 <DEPRECIATION> 12,975 <TOTAL-ASSETS> 54,863 <CURRENT-LIABILITIES> 7,565 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 72 <OTHER-SE> 42,454 <TOTAL-LIABILITY-AND-EQUITY> 54,863 <SALES> 46,505 <TOTAL-REVENUES> 46,505 <CGS> 26,580 <TOTAL-COSTS> 26,580 <OTHER-EXPENSES> 15,274 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 208 <INCOME-PRETAX> 4,766 <INCOME-TAX> 1,930 <INCOME-CONTINUING> 2,836 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 2,836 <EPS-BASIC> 0.40 <EPS-DILUTED> 0.37