In a review of the records of 3,712 drug abusers, 13 patients were identified with neurologic deficits attributable to the use of cocaine. Ischemic manifestations were the most frequent, occurring in seven (54%) patients, with a mean age of 34.2 years. Three (23%) patients had subarachnoid hemorrhage, and three (23%) had intracerebral hemorrhage. Three patients from other institutions were included in the analysis, for a total of 16 patients, (eight with cerebral ischemia, four with subarachnoid hemorrhage, and four with intracerebral hemorrhage). Of the six patients with head computed tomographic findings of cerebral infarction, five had subcortical infarcts. Two of the four patients who presented with a subarachnoid hemorrhage had a congenital intracranial aneurysm. One of the four patients with an intracerebral hemorrhage had an underlying arteriovenous malformation. The mechanism through which these complications occur is not completely understood. Factors that may play a role include the acute hypertensive response that occurs with cocaine use as well as disordered neurovascular control.