Recent statistics from the National Institute on Drug Abuse indicate that cocaine abuse continues to be a significant public health problem. Between 1988 and 1990 at Grady Memorial Hospital in metropolitan Atlanta, Georgia, we identified 12 patients in whom subarachnoid hemorrhage was temporally related to cocaine abuse. All 12 patients had underlying cerebral aneurysms that had ruptured. Currently, the incidence of ruptured intracranial aneurysms in patients with cocaine-induced subarachnoid hemorrhage is 84.9% (mean age, 31.1 years; overall mortality, 60.5%). Hypertension is the likely precursive factor in cocaine-induced aneurysmal rupture. Cocaine abuse appears to be a significant negative factor in the natural history of cerebral aneurysms, especially in young adults. We review the epidemiology of cocaine-induced subarachnoid hemorrhage and its effects on the cerebral circulation, and suggest guidelines for patient management.