The automated immunoassay analyser, IMMULITE, developed by DPC, was evaluated. IMMULITE is an automated system that allows random access in combination with immediate and continuous access. In this study we evaluated the IMMULITE on four panels of analytes: thyroid, fertility, tumour and "non-routine" markers. We observed good within-rum reproducibility (ranging from 2.3-15.9% CV, for low controls, to 2.7-8.7% CV for high controls) as well as between-day imprecision (ranging from 3.7-24.6% CV for low controls, to 2.5-11.8% cv for high controls). The analytical sensitivity of the assays ranged generally from very sensitive to acceptable. The dilution curves for all assays were nearly linear i.e. the maximum deviation of the observed from the expected recovery was 8%. Correlation between IMMULITE and other assays (AxSYM, IMx, TDx, AIA-1200, DPC-c. a. c., Medgenix) varied from r = 0.931 to r = 0.994, except for lutropin and parathyrin with coefficients of correlation of r = 0.594 and r = 0.591. The slopes of the regression lines ranged from 0.745 to 1.327, except for parathyrin where a slope of 2.389 was found. Inter-laboratory correlation was very good between the two locations (Sittard and Apeldoorn) and varied from r = 0.984 to r = 0.999; slopes of the regression lines varied from 0.924 to 1.086. We conclude that the DPC-IMMULITE system is suitable for testing routine analytes in random access mode as well as for testing "non-routine" analytes on an automated immunoassay analyser.