The external carotid artery (ECA) is an underestimated but important collateral to the cerebral hemisphere and eye in patients with severe disease of the internal carotid artery. Fifteen symptomatic patients with total occlusion of the internal carotid artery underwent ECA reconstruction. Ipsilateral ECA reconstruction was performed upon all patients with no mortality or neurologic deficits. Contralateral disease of the carotid artery was noted in 11 and required correction in seven patients. Follow-up study of the patients ranged from one to 68 months (a mean of 26.8 months) after operation. Vertebrobasilar symptoms persisted in two patients, both with contralateral disease. One of these patients successfully underwent extracranial-intracranial bypass. One ipsilateral and one contralateral stroke occurred during follow-up study, both in patients with contralateral disease. Eleven patients were alive and asymptomatic at last follow-up examination. Symptomatic selected patients with occlusion of the internal carotid artery and ECA stenosis or cul-de-sac formation should be considered for operation. ECA reconstruction is associated with little morbidity and three-fourths of the patients remain asymptomatic. A high incidence of contralateral disease of the carotid artery is present. Extracranial-intracranial bypass should only be considered when symptoms persist after correction of contralateral disease of the carotid artery and any ECA lesions.