Cerebral angiography and CT brain scan are performed on a group of 174 patients (28 asymptomatic patients; 109 patients with symptoms of stroke in relation with a clinically defined vascular territory; 37 patients with symptoms in relation with a clinically uncertain vascular territory). Angiographic findings are: cervical artery lesions in 143 patients, brain artery lesions in 6 patients, both extra and intra cranial artery lesions in 22 patients, and non atheromatous artery lesions in 3 patients. CT brain scan shows: hypodensity in 19 cases, hyperdensity in 1 case, cortical and/or sub cortical atrophy in 141 cases. Only 13 patients have normal CT brain scan. Authors also note: 4 infarction areas in asymptomatic patients and only 4 hypodensities out of 21 cases of internal carotid artery occlusion. Ulcerated cervical artery lesions seem to be the main cause (73%) of cerebral infarction.