Despite advances in understanding the epidemiology and pathophys-iology of cerebrovascular disease, stroke remains the third leading cause of death in the United States. Although hypertension is the most important treatable risk factor for stroke, recent epidemiologic studies have found elevated cholesterol, oral contraceptive use, alcohol abuse, and cardiac defects to be independent risk factors for stroke. Recently published clinical trials add to our ability to prevent and treat stroke. Aspirin remains the most commonly used antiplatelet agent affording reductions of about one third in nonfatal stroke in patients at high risk. Ticlopidine has been shown to have a slight benefit over aspirin in preventing stroke and transient ischemic attack, but this drug has more adverse effects. In pooled data from five clinical trials, warfarin was found to be superior to aspirin in preventing stroke in patients with atrial fibrillation. Early clinical trials with neuroprotective and thrombolytic therapies have shown promise, but large prospective randomized trials are still in progress. The indications for carotid endarterectomy continue to be defined; however, surgical intervention appears to benefit both symptomatic and asymptomatic patients with high-grade carotid stenosis.