The authors report on a series of 100 patients, who underwent an ischemic cerebrovascular accident (CVA) (8 transient attacks, 15 minor CVAs and 77 completed strokes) which revealed internal carotid artery occlusion (unilateral in 93 cases and bilateral in 7), proven by ultrasonography and/or angiography. The computerized tomography scan was normal in 8 cases. The middle cerebral artery territory was involved in 84 patients (isolated or associated (25 patients) with another site), whereas an isolated watershed infarction was the only lesion in the other 8 patients. Twenty-two patients died during the acute phase. Among the 68 survivors followed for a long time, 28 were severely incapacitated. The occlusions were not atherosclerotic in 18 cases (8 spontaneous dissections, 5 cardiogenic emboli, 3 radiation-induced arteries, 2 multiple causes). Eighty-two patients had atherosclerotic thromboses (67 men and 15 women, mean age 63.1 +/- 12.7 years). Among them, 24 had previously experienced minor ischemic strokes. In this group, the two year survival rate was 63 p. 100. Patients with non-fatal atherosclerotic thromboses were followed for an average of 22.2 months, during which time 28.2 p. 100 experienced another stroke.