A 54-year-old female, who had been treated for aplastic anemia by metenolone acetate since 1981, developed a sudden unconsciousness in September 1995. On admission, she was drowny, CT showed a subarachnoid hemorrhage (SAH) in the right Sylvian fissure. Angiography demonstrated a complete occlusion of the superior sagittal sinus. The SAH was assumed to be originated from rupture of the right Sylvian vein, which was irregularly dilated on angiography. The dural sinus thrombosis was thought to be caused by a long term use of metenolone acetate, and it was discontinued. But her platelet count dropped due to the aggravation of aplastic anemia, and she developed repeated hemorrhagic infarction. An active anticoagulant therapy for the dural sinus thrombosis was thought to be inappropriate because she had the aplastic anemia and the hemorrhagic infarction recurred. We have successfully treated this case by mild anticoagulant therapy with nafamostat mesilate (Futhan).