Keeping firearms at home may increase personal safety but it may also increase the risk of injury. This study uses data from three waves of the National Longitudinal Study of Adolescent Health to assess the extent to which adolescents' easy access to firearms at home increases the risk of violent offending and violent victimization. Access to firearms was higher for males, Whites, and adolescents having two parents, especially fathers. Current access to firearms at home significantly increased the odds of both violent offending and violent victimization, even after controlling for prior access, prior offending, and prior victimization. This relationship persisted into early adulthood; access to firearms still significantly increased the odds of violent offending and violent victimization. (Contains 7 tables.)