Cerebral thromboembolic stroke in the young is uncommon. Disturbances in the n ormally existing dynamic equilibrium between coagulation and fibrinolysis may play a major role in the pathogenesis of such episodes. In a search for a possible hypercoagulable state platelet adhesiveness by the method of Eastham, plasma fibrinogen and euglobulin clot lysis times were estimated in 46 patients. A group of 15 normal subjects matched for age and sex were also studied for comparison. Significant increase in platelet adhesiveness (P less than 0.001) and plasma fibrinogen (P less than 0.001) was noted in the patients when compared with the normal subjects. Absence of corresponding increases in fibrinolytic activity in the patients suggests disturbed equilibrium between coagulation and fibrinolysis. The possibility of a hypercoagulable state in these cases is discussed.