Our motivation for undertaking the present survey was to determine the incidence, the distribution, and the clinical features of ischemic and hemorrhagic strokes in children under 16 years old, in a well-defined population-based study. The survey was carried out on the population of the City of Dijon (150,000 inhabitants) from January 1, 1985 to December 31, 1993, collecting prospectively both in adulthood and in childhood (23,877 resident children). Diagnosis of stroke was established ion the basis of clinical features and the mechanism was identified by CT scan from 1985 to 1987, and by CT scan and magnetic resonance imaging from 1987 to 1993. When a hemorrhagic stroke was identified, a cerebral arteriogram and an investigation of the coagulation factors were performed. When an ischemic stroke was identified, the following were performed: an ultrasound examination of the cervical arteries, a cerebral arteriogram, a lumbar puncture, an investigation of the coagulation factors and lipid status, a measurement of homocystine in the plasma and the urine, an electrocardiogram (EKG), a Holter procedure, and a cardiac echography. During the 9 full calendar years of this study we observed 28 stroke patients from a population of 23,877 resident children. There were 17 cases of ischemic stroke, representing some 61% percent of the total, as well as 11 cases of hemorrhagic stroke, 39% percent of the total. The average annual incidence rate was 13.02/100,000 for all strokes, 7.91/100,000 for ischemic strokes, and 5.11/100,000 for hemorrhagic strokes. Of the 17 cases with ischemic stroke, 2 had no known predisposing condition, 3 occurred in children witn preexisting heart disease, and 12 were observed in patients with other associated conditions such as infections or slight cranial trauma. On CT scan, a basal ganglia infarction was identified in eight cases. Among the 11 hemorrhagic strokes, 9 were due to vascular malformations. Clinical course was marked by a higher mortality rate in hemorrhagic stroke, no long-lasting seizures, and hemidystonia. Therefore, this epidemiological survey focused on the real place of stroke in children under 16 years of age, compared to the large place occupied by stroke in adulthood. Ischemic strokes were more frequent than that reported in the literature. Risk factors were identified in the majority of children, and followup demonstrated good or complete resolution of neurological deficits despite the frequent late hemidystonia.