Two hundred and nineteen cases with aneurysmal subarachnoid hemorrhage treated at Chang Gung Memorial Hospital from January 1986 to December 1989 were studied. Their ages ranged from 19 to 76, with a mean of 55 +/- 16 years. About one third of the cases occurred in the age group of 50 to 59 years. Females were predominant with a female to male ratio of 2:1, but there was a male predominance below age 40. The most common site of aneurysm was the anterior communicating artery. Rebleeding, delayed vasospasm with cerebral infarction, and hydrocephalus were the main causes of death or disability. The mean follow-up of 6 months for the whole group showed a 59% favorable outcome, 13% severe disability and a 28% mortality. For those 166 patients who underwent surgical treatment, there was 8% mortality.