The authors investigated 100 patients (55 males and 45 females) aged 16 to 45 years who experienced cerebral ischemic attack, excluding venous thrombosis. Transient ischemic attacks accounted for 12% only. Attacks were related to usual causes of brain ischemia in 49 cases (premature atherosclerosis in 26, cardiopathy in 20 and lacunar stroke in 3). Thirty-eight events were attributed to most uncommon etiologies. Nonatherosclerotic arteriopathies (10 cases) such as spontaneous dissection, dysplasia or megadolichoarteries were easily diagnosed by angiography. Oral contraceptives (14 cases) and migraine (2 cases) were diagnosis of exclusion. Hematological disorders were a possible cause in 10 patients. Etiology remained undetermined in 13 cases. Four patients died acutely. Follow-up data were obtained in 93 survivors with a mean duration of 26 months (range, 6 to 60 months). Four subjects died during follow-up and 6 experienced recurrent stroke (annual recurrence rate: 3%). In activities of daily living, 64% of patients had complete autonomy while 13% had mild residual disability and 23% had severe handicap.