Pregnancy is a hypercoagulable state secondary to an increase in the concentrations of procoagulant factors, reduction in the concentrations of the naturally occuring anticoagulant proteins, and in fibrinolysis. An exaggerated hemostatic response during pregnancy results in thrombosis of the uteroplacental vasculature and subsequent fetal loss. The study comprised 50 women suffering from recurrent spontaneous abortions. Also a control group of 10 parous women with no previous history of adverse pregnancy outcome was included. The women were tested for the factor V Leiden & prothrombin G20210A mutations using reversed hybridization technique using normal & mutated probes for both coagulation factors & the amplified patient DNA. They were also tested for activated protein C resistance using chromogenic method of Coatest and for deficiency of protein C, protein S or antithrombin III, and for the presence of circulating lupus anticoagulant (clotting assay), and anticardiolipin antibodies IgG & IgM (ELISA). The factor V Leiden mutation was found in 2/50 (4%) of cases and not found in the control group. Protein C, protein S or antithrombin III deficiency were found in 11/50 (22%) of patients, and the presence of lupus anticoagulant or anticardiolipin antibodies were detected in an additional 20% of the studied patients. Activated protein C resistance was found in 14% of patients and 4% of them were heterozygous for the factor V Leiden mutation. Prothrombin gene mutation was not detected in both studied groups of patients and controls.