A historical cohort study was undertaken to determine the risk of epilepsy in a population of 371 newborns with an acute neurological disorder related to fetal and/or neonatal hypoxia compared with a control population of 362 normal newborns. The results showed that the risk of epilepsy was 5.1 times higher in the group of subjects affected at birth by a hypoxia-related acute neurological syndrome than in the control group. (Although the incidence of epilepsy is higher in the first year of life, epileptic seizures connected to perinatal hypoxia may occur in early childhood or later on.) Also, there were frequently persistent neuropsychiatric disorders in children with perinatal hypoxia (5.4%). There was no difference in the two groups regarding the incidence of febrile convulsions. The data show that perinatal hypoxia plays a role in the etiology of epilepsy, although at birth the hypoxia might result in only a modest and oftentimes completely reversible neurological syndrome.