A case of thrombosed aneurysm of the vein of Galen associated with superior sagittal sinus thrombosis is reported. Clinical course was characterized by multiple intraparenchimatous hemorrhages and hydrocephalus. NMR showed dural sinuses thrombosis better than CT even though cerebral angiography was more effective for the diagnosis. Intracranial hypertension due to hydrocephalus was relieved with a ventriculoperitoneal shunt. The authors suggest that the abnormal hemodynamic patterns due to the drainage of the malformation into the vein of Galen and dural sinuses led to venous occlusion and multiple intracranial hemorrhages.