We describe eight patients in whom cocaine use was related to stroke and review 39 cases from the literature. Among these 47 patients the mean (+/- SD) age was 32.5 +/- 12.1 years; 76% (34/45) were men. Stroke followed cocaine use by inhalation, intranasal, intravenous, and intramuscular routes. Intracranial aneurysms or arteriovenous malformations were present in 17 of 32 patients studied angiographically or at autopsy; cerebral vasculitis was present in two patients. Cerebral infarction occurred in 10 patients (22%), intracerebral hemorrhage in 22 (49%), and subarachnoid hemorrhage in 13 (29%). These data indicate that (1) the apparent incidence of stroke related to cocaine use is increasing; (2) cocaine-associated stroke occurs primarily in young adults; (3) stroke may follow any route of cocaine administration; (4) stroke after cocaine use is frequently associated with intracranial aneurysms and arteriovenous malformations; and (5) in cocaine-associated stroke, the frequency of intracranial hemorrhage exceeds that of cerebral infarction.