The number of fatal brain injuries and hospital admissions for brain injuries in children up to 15 years old in San Diego County, California, were ascertained from emergency room and hospital records, coroners' reports, death certificates, and nursing home and extended-care records for 1981. The annual brain-injury rate per 100 000 children was 185 (235 for boys and 132 for girls). The major causes of pediatric brain injury were falls (35%), recreational activities (29%), and motor vehicle crashes (24%). The case-fatality ratio was six deaths per 100 injured children. Of those children admitted to a hospital alive, 88% had a mild brain injury and 44% had no evidence of loss of consciousness. Two thirds of children with mild brain injuries and one third of those with serious brain injuries were transported to a hospital in private nonemergency vehicles.