Objective : pre-eclampsia remains amajor cause of maternal and fetal ill-health .Platelet activation occurs in early pregnancy in women at risk of developing per-eclampsia. This disease seems to be linked to oxidative stress within the plancenta and increased production of lipid peroxides. Our purpose is to study the hemostatic functions of blood in per-eclampsia and the protective effect of vitamin E as an antioxidant in pervention of induced per-eclamipsia. METHODS: pre-eclamipsia is induced in pregnant rats by intraperitoneal injection of nitric oxide synthase inhibitor ( L-NAME ) from the 14 day of pregnancy. % platelet aggregation ,prothrombin time and fibrinogen level were estimated in normal pregnancy , per-eclampsia and after treatment of these groups with vitamin E . RESULTS: Aggregation increased in pre-eclamipsia which upon tretment with vitamin E returned to the normal pregnant level . CONCLUSION: vitamin E plays important role in amelioration of the hypercoagulable state which occurs in pre-eclmpsia .