This study compares injuries of restrained and unrestrained 4- to 14-year-olds in nine emergency rooms and the Coroner's office in Orange County, California from 1983 to 1989. Analyses were performed separately for 4- to 9- and 10- to 14-year-olds because of differences related to the fit of the seat belt. Significantly fewer intracranial injuries and a significantly lower mean Injury Severity Score (ISS) were seen between the restrained and unrestrained for 10- to 14-year-olds in the front passenger and back seats; but for 4- to 9-year-olds in the back seat only. These same differences were noted between restrained 4- to 9-year-olds in the back compared with those in the front passenger seat. Except for 4- to 9-year-olds in the front passenger seat, our findings are consistent with similar studies of occupants of all ages. Our results suggest that lap-shoulder belts (primary restraint in front seat) may provide less protection for 4- to 9-year-olds than for 10- to 14-year-olds and adults.