Data from the National Longitudinal Survey of Youth 1997 were used to examine factors associated with carrying a handgun among adolescent males. We expected that carrying a handgun would be associated with characteristics of the individual and with aspects of the contexts that are important for adolescents, such as the family, the peer group, the school setting, and the neighborhood. Consistent with these expectations, we found that adolescent males were more likely than their peers to carry handguns if they engaged in other problematic behaviors, had witnessed someone else being shot or shot at, and were involved in gangs. Boys under the age of 15 were less likely to carry a handgun if they were closely monitored by their mothers and respected their mothers, and they were more likely to carry a handgun if they frequently heard gunshots in their neighborhood or had a relative or friend who was a gang member. Males who were 15 and older were more likely to carry a handgun if they associated with peers who engaged in problematic behaviors.