<ARTICLE> 5 <CIK> 0001022079 <NAME> Quest Diagnostics Incorporated <MULTIPLIER> 1000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> JUN-30-1997 <CASH> 75,834 <SECURITIES> 0 <RECEIVABLES> 287,987 <ALLOWANCES> 108,622 <INVENTORY> 27,921 <CURRENT-ASSETS> 523,470 <PP&E> 273,140 <DEPRECIATION> 309,262 <TOTAL-ASSETS> 1,397,193 <CURRENT-LIABILITIES> 251,466 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 1,000 <COMMON> 1,183,046 <OTHER-SE> (622,834) <TOTAL-LIABILITY-AND-EQUITY> 1,397,193 <SALES> 789,626 <TOTAL-REVENUES> 789,626 <CGS> 478,907 <TOTAL-COSTS> 730,734 <OTHER-EXPENSES> 897 <LOSS-PROVISION> 59,825 <INTEREST-EXPENSE> 21,112 <INCOME-PRETAX> 24,861 <INCOME-TAX> 12,726 <INCOME-CONTINUING> 12,135 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 12,135 <EPS-PRIMARY> 0.42 <EPS-DILUTED> 0.42