A retrospective study of 129 carotid artery reconstructions with an occlusion of the contralateral internal carotid artery (group CO) is presented. A control group comprised 489 patients with a stenosis of < 50% at the contralateral side (group CN). Both groups had the same mean age. There were fewer women in group CO (14% versus 31%, P < 0.0001), and more patients had a history of coronary heart disease (57% versus 44%, P < 0.05). In addition more patients of group CO had suffered a stroke (36% versus 27%, P < 0.05). A temporary shunt was used selectively and more frequently in group CO (87% versus 31%, P < 0.001). Major postoperative complications occurred with equal frequency in both groups: all strokes plus non-cerebral mortality (total combined morbidity and mortality): 4.65% versus 5.5%. The late incidence of stroke was the same in both groups: 8% in CO and 7% in CN at 5 years. The authors conclude that, under the described circumstances and with the appropriate surgical technique, the presence of an occlusion of the contralateral internal carotid artery does not imply an increase in major postoperative complications nor a higher stroke rate during follow-up.