• One or more nonfebrile seizures occurred between the ages of 1 month and 7 years in eight per 1000 white and in nine per 1000 black children enrolled in a large prospective study. We examined hundreds of prenatal and perinatal factors as predictors of childhood seizure disorders. Congenital malformations of the fetus (cerebral and noncerebral), family history of certain neurologic disorders, and neonatal seizures were the major predictors identified. Forty percent of children with postneonatal seizures and 68% of children with minor motor seizures had one or more of these risk factors compared with 21% of the seizure-free population. More than half of the children with minor motor seizures and a third of the infants with neonatal seizures had congenital malformations. Based on the prenatal and perinatal factors examined, prediction of postneonatal seizures carried a high rate of false-positive identification, indicating that our knowledge of the etiology of childhood seizure disorders is still very limited.