Prospective screening of 449 patients undergoing coronary or peripheral arterial revascularization detected asymptomatic cervical bruits in 44 patients (9.8%) and carotid obstruction by Doppler ultrasound in 63 individuals (14.0%). There was poor correlation between cervical bruit and carotid obstsruction. No patient underwent prophylactic casrotid endarterectomy. Three patients had transient ischemic attacks (TIAs), and five had nonfatal strokes perioperatively, only one of which was in the territory appropriate to carotid obstruction. Of 72 surviving patients with asymptomatic carotid disease, 10 (13.9%) had TIAs and one (1.4%) died of stroke during a 2-year follow-up, during which time only two (0.8%) of 254 patients without carotid disease reported symptoms of TIAs. Patients with asymptomatic carotid disease had a significantly higher incidence of perioperative and late deaths (10.6% and 9.2%, respectively), usually of myocardial infarction, as compared to patients without carotid disease (0.3% and 0.8%, respectively, P less than 0.001). Asymp-tomatic carotid disease, although correlating poorly with perioperative stroke in patients undergoing cardiovascular operations, identifies patients at risk of late neurologic events and peroperative or late deaths from myocardial infarction. We do not recommend prophylactic carotid endarterectomy but favor operative intervention if patients develop TIAs during a period of careful follow-up .