In this prospective study we report the outcome for all patients with a verified aneurysmal SAH managed at the Department of Neurosurgery at the University Hospital in Lund, Sweden during the four-year span from June 1, 1989 to May 31, 1993. A total of 275 patients were admitted during the study period. The vast majority of patients (196 individuals, i.e. 71%) was admitted within 24 h after the bleed. Mean age was 54.3 years and the female/male ratio 1.8/1. Nimodipine was administered in 231 (84%) of the 275 patients. We clipped the ruptured aneurysm in 199 patients. At follow-up 3 months after the bleed 161 patients were classified as having made a good neurological recovery (59%). The morbidity was 20% and 59 patients (21%) had died. The overwhelming cause for morbidity and mortality was damage from the initial bleed (62 patients, 23%). Notably, considering morbidity and mortality, delayed ischemia was less frequent than both surgical complications and rebleeding, respectively. Of the 275 patients, 13 (5%) patients made an unfavorable outcome due to delayed ischemic deterioration. There was a strict correlation between the initial clinical condition and final outcome. Of 51 grade V patients, only 2 made a good recovery. There was also a strict correlation between the amount of extravasated blood and outcome. There was no difference in clinical outcome between patients with arterial hypertension versus normotensive individuals. The mortality rate was worse for posterior circulation aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)