One hundred patients with spontaneous subarachnoid hemorrhage due to aneurysm or presumed aneurysm consecutively admitted to a neurological clinic and subjected to CCT during the first 72 hours were examined retrospectively. The outcome after two months as defined by the Glasgow Outcome Scale (GOS) was relatively good: 23% of the patients suffered management mortality (GOS I) (postoperative lethality 8%), 3% showed GOS-Grade II, 14% grade III, 17% grade IV, and 43% grade V. The extent of intracranial hemorrhage correlated well with the initial Hunt-Hess Grade which, in turn, had a strong influence on case fatality and the degree of disability. Lethal factors were: 1. massive subarachnoid hemorrhage together with a massive ventricular hemorrhage (p < 0.001), 2. massive subarachnoid hemorrhage together with an intracerebral hematoma > 20 ml (p < 0.05). Case fatality was lower when angiography was negative. In our study rebleeding (12%) and delayed cerebral ischemia (DCI) (18%) were less frequent and the lethality due to acute hydrocephalus (5%) and delayed cerebral ischemia (5%) was less pronounced than in comparable studies. The degree of disability (GOS) was directly related to the amount of intracranial blood, to the development of acute or chronic hydrocephalus, delayed cerebral ischemia and rebleeding. DCI occurred in 60% of patients with marked hydrocephalus. Rebleeding was more frequent in patients with acute hydrocephalus. Hydrocephalus, DCI, and rebleeding were associated with a poorer initial grade on the Hunt and Hess Scale.