In a previous prospective study of 449 patients undergoing coronary or peripheral arterial reconstruction, 85 patients had preoperative evidence of asymptomatic bruit and/or greater than 50% carotid obstruction by routine Doppler screening. No patient had prophylactic carotid endarterectomy. This article reviews the late postoperative outcome (2 to 61 months, mean 35 months) of 67 patients with asymptomatic carotid disease who survived operation without perioperative deficit. Eleven patients died (16%) including four of myocardial infarction and two of stroke. Neurologic deficits occurred in the late postoperative period in 22 patients (32.8%) after an average interval of 31 months, including transient ischemic attacks in 15 patients (22.4%); only four of these 15 were appropriate to the side of carotid disease documented preoperatively. Seven patients (10.4%) suffered stroke, only three (4.5%) of which were in the territory of carotid disease detected preoperatively. The cumulative rate of carotid disease progression was 34%, including three patients who suffered carotid occlusion. Two of the latter had the only fatal strokes. This study suggests that patients with asymptomatic carotid disease, although not at significant risk of perioperative stroke, require careful follow-up for late postoperative neurologic deficits, the majority of which (68%) are transient ischemic attacks.