In Nicaragua the rise of urban youth gangs has led the government to adopt a crime-control approach that focuses on containing adolescent violence. Yet efforts to foil youth gangs have been ineffectual, largely because the nature of gang membership is little understood. This article presents the results of a qualitative study of youth gang membership in the capital city of Managua. From participant observations and interviews with a cohort of youth gang members and a number of people closely attached to them, the study presents youth perspectives of gang membership in a way that underscores the dialectic between individual agency and the structural environments that impinge on youth choices. The study concludes by arguing that policies aiming to deal with urban youth gangs in Nicaragua must accommodate the perspectives of marginalized urban youth and draw upon their capacity for individual and collective agency. (Contains 8 notes.)