Book excerpt: Although a well-known phenomenon in the U.S., street gangs and other violent and criminal groups_including racist groups_exist also in European cities and countries, and are of increasing concern in global law enforcement. The eminent contributors to this volume present valuable new data on European youth gangs, describing important characteristics of these groups, and their similarities and differences to American gangs. Their findings from the Eurogang Research Program compare European and American gang interventions, and highlight the impact of immigration and ethnicity, urbanization, national influences, and local neighborhood circumstances on gang development in several European countries. It is an important resource on crime, delinquency and youth development for criminologists, sociologists, youth workers, policy makers, local governments, and law enforcement professionals.