PurposeWhile bicycle helmet use reduces bicycle-related head injury, few children wear them regularly. We aimed to describe racial/ethnic and socioeconomic differences in pediatric helmet use in Los Angeles County (LAC) to help target groups for injury prevention programs. MethodsA retrospective review of all pediatric patients involved in bicycle-related accidents in LAC between 2006 and 2011 was performed. Our primary analysis examined the association between helmet use and age, gender, insurance status, and race/ethnicity. We also evaluated the association between helmet use and the need for emergency surgery, mortality, and length of hospital stay (LOH), after adjusting for injury severity score (ISS), age, insurance status, and race/ethnicity. ResultsOf 1248 patients, 11.3% wore helmets, with decreased use among children 12years and older, minorities, and those without private insurance. Overall, 5.9% required an emergency operation, 34.1% returned to their pre-injury capacity, and mortality was 0.7%. On multivariable analysis, higher ISS increased LOH, the risk for emergency surgery, and mortality. ConclusionNearly 90% of children involved in bicycle-related accidents were not wearing helmets. Helmet use was lower among older children, minorities, and those from a low socioeconomic status. Injury prevention programs targeting low-income middle and high schools and minority communities may help increase helmet use in children in LAC.