Despite a decline in the incidence of homicide in recent years, the United States retains the highest youth homicide rate among the 26 wealthiest nations. Homicide is the second leading cause of death overall and the leading cause of death for male blacks aged 15 to 24 years. High rates of health care recidivism for violent injury, along with increasing research that demonstrates the effectiveness of violence prevention strategies in other arenas, dictate that physicians recognize violence as a complex preventable health problem and implement violence prevention activities into current practice rather than relegating violence prevention to the criminal justice arena. The emergency department (ED) and trauma center settings in many ways are uniquely positioned for this role. Exposure to firearm violence doubles the probability that a youth will commit violence within 2 years, and research shows that retaliatory injury risk among violent youth victims is 88 times higher than among those who were never exposed to violence. This article reviews the potential role of the ED in the prevention of youth violence, as well as the growing number of ED- and hospital-based violence prevention programs already in place.