The sensitivity, specificity and reproducibility of the solid phase capture-platelet test (CPT) were compared with those of the platelet adhesion immunofluorescence test (PAIFT) and the lymphocytotoxic test (LCT). This study shows that CPT has a higher sensitivity than PAIFT (P < 0.001) and LCT (P < 0.01). The specificity was 86% lower than LCT (100%) (P < 0.01). Both the CPT test and PAIFT were comparable with regard to reproducibility (100%, 92%). The solid phase assay is easier to handle than PAIFT and LCT, allowing identification of HLA as well as of platelet specific antibodies. It is an efficient antibody screening test.