The present prospective study, with participation of five of the six neurosurgical centers in Sweden, was conducted to evaluate the overall management results in patients with aneurysmal subarachnoid hemorrhage (SAH). The participating centers covered 6.93 million (81%) of Sweden's 8.59 million inhabitants. All patients with verified aneurysmal SAH admitted between June 1, 1989, and May 31, 1990, were included in this prospective study. A uniform management protocol was adopted involving ultra-early referral, earliest possible surgery, and aggressive anti-ischemic treatment. A total of 325 patients were admitted during the study period, 69% within 24 hours after hemorrhage. On admission, the patients were graded according to the scale of Hunt and Hess: 43 patients (13%) were classified in Grade I, 119 (37%) in Grade II, 53 (16%) in Grade III, 76 (23%) in Grade IV, and 34 (11%) in Grade V. Nimodipine was administered to 269 of the 325 patients: intravenously in 218, orally in 15, and intravenously followed by orally in 36. At follow-up examination 3 to 6 months after SAH, 183 patients (56%) were classified as having made a good neurological recovery, 73 patients (23%) suffered some morbidity, and 69 (21%) were dead. Surgery was performed in 276 (85%) of the patients; emergency surgery with evacuation of an associated intracerebral hematoma was carried out in 30 patients. Early surgery (within 72 hours after SAH) was performed in 170 individuals, intermediate surgery (between Days 4 and 6 post-SAH) in 29 patients, and late surgery (Day 7 or later after SAH) in 47 individuals. Of 145 patients with supratentorial aneurysms who were preoperatively in Hunt and Hess Grades I to III and who were treated within 72 hours, 81% made a good recovery; in 5.5% of patients, the unfavorable outcome was ascribed to delayed ischemia. It is concluded that, among patients with all clinical grades and aneurysmal locations, almost six of 10 SAH victims referred to a neurosurgical unit can be saved and can recover to a normal life.