Bicycle injuries are the most common cause of serious head injury in children, and most of these injuries are preventable. The protective effect of bicycle helmets is well documented, but many child bicyclists do not wear them. This article summarizes the current state of research on bicycle injuries and helmet use and examines the effectiveness of legislation and injury-prevention strategies. Current studies indicate that children who wear helmets experience fewer head injuries and decreased severity of injury. Community-wide helmet-promotion campaigns combined with legislation are most successful in increasing helmet use and decreasing injury. Nurses can participate both at the institutional level and in community advocacy groups to promote bicycle safety for children.