With nearly 8,000 gangs and 200,000 gang members, Los Angeles holds the dubious distinction of being the youth gang capital of the United States. The process of street socialisation that leads to gang membership now cuts across all ethnic groups, as evidenced by the growing numbers of gangs among recent immigrants from Asia and Latin America. This cross-cultural study of Los Angeles gangs identifies the social and economic factors that lead to gang membership and underscores their commonality across four ethnic groups - Chicano, African American, Vietnamese, and Salvadorian. James Diego Vigil begins at the community level, examining how destabilising forces and marginalising changes have disrupted the normal structures of parenting, schooling, and policing, thereby compelling many youths to grow up on the streets. He then turns to gang members' life stories to show how societal forces play out in individual lives. His findings provide a wealth of comparative data for scholars, policymakers, and law enforcement personnel seeking to respond to the complex problems associated with gangs. James Diego Vigil is Professor of Social Ecology at the University of California, Irvine.