The primary risk factors for stroke are known, and attention to primary care of these disorders should reduce the incidence of stroke significantly. Control of hypertension, diabetes, and hyperlipidemia have all been shown to reduce the rate of stroke. Identification of potential cardioembolic sources of stroke, particularly atrial fibrillation, can prevent stroke with appropriate application of anticoagulation. Duplex Doppler B-mode sonography can establish the extent of carotid artery disease in patients with cervical bruit or risk factors for atherosclerosis, and indicate which conditions should be managed medically or surgically. Patients with a history suggestive of transient ischemic attacks can also be screened noninvasively with duplex sonography to determine if they have a critical carotid stenosis and require carotid endarterectomy. New advances in platelet antiaggregant therapy with ticlopidine, clopidogrel, and the combination of aspirin with dipyridamole have also reduced the rate of stroke to a greater degree than standard treatment with aspirin. The incidence of this devastating illness could possibly be reduced by 50% with attentive primary care management. The cardiologist is often involved in the treatment of patients at risk for stroke, and is in an ideal position to provide this care.