Changes in the practice of carotid endarterectomy were studied by review of all endarterectomies performed in the greater Cincinnati area during 1980 and from July 1983 through June 1984. The number of operations rose from 431 to 750 (74% increase). The perioperative stroke rate fell from 8.6% in 1980 to 5.1% in 1983-1984; operative mortality declined from 2.8% to 2.3%; and the combined stroke or death rate declined from 9.5% to 6.5%. Asymptomatic carotid artery disease was the indication for 50% of the endarterectomies during both time periods. The combined stroke or death rate for asymptomatic patients declined from 6.9% to 5.3%, but both rates were higher than the 3% suggested as acceptable for prophylactic carotid endarterectomy. We conclude that carotid endarterectomy is becoming an increasingly common procedure, that morbidity continues to decline, and that mortality continues to be significant. Citywide surgical morbidity and mortality remain excessive for patients with asymptomatic carotid disease.