In 101 patients 114 asymptomatic carotid stenoses were treated operatively, complicated by one lesion of hypoglossic nerve and one temporary neurologic deficit. During the follow-up period of 6-89 months cardiovascular diseases were seen in 60% of the patients. There were 9 late deaths, 5 due to myocardial infarction and 2 due to contrahemispheric cerebral ischemia. TIA's or cerebral infarctions were not observed in the hemisphere corresponding to the operated carotid artery. Interdisciplinary patient selection, non-invasive diagnostics and selective shunt protection are considered to be essential risk reducing factors.