We estimated the event rates for stroke and transient cerebral ischemic attacks in a prospective community-based epidemiologic study in a representative segment of the city of Perth, Western Australia, during a 10-month period in 1986. Of 349 persons with an initial diagnosis of stroke or transient ischemic attack, 154 had suffered a first stroke, 75 a recurrent stroke, and 47 a transient ischemic attack; the remaining 73 persons were thought not to have had an episode of acute cerebrovascular disease. Annual event rates for first stroke (age-standardized to the "world" population) were 120 per 100,000 for males and 56 per 100,000 for females. The crude case-fatality ratio at 28 days after the index event for first stroke was 23% and varied from 0% for lacunar infarction to 57% for subarachnoid hemorrhage.