Public officials and criminologists tend to explain the increase in youth violence in terms of family deterioration, school failure, poverty, drugs, firearm availability, and disorganized communities. Current knowledge of street gangs and gang-related crime, however, is limited. One study of gangs in 26 U.S. cities indicated that problems with youth gangs were reported by all or almost all respondents in nine cities, by a majority of respondents in eight cities, and by a few respondents in five cities. Virtually all respondents in the 26 localities also reported problems with groups other than gangs. Gang members ranged in age from 10 to 21 years; they accounted for about 11 percent of all arrests of male youth and 42 percent of arrests for serious and violent crimes. Gang members were less likely to be arrested for drug offenses than were nongang youth, although evidence indicated increasing gang involvement in the drug trade. Another study conducted a comprehensive national survey of organized agency and community group responses to the gang problem. Of 254 respondents surveyed in 45 cities, gang prevention was accomplished mainly through community organization and suppression strategies. The Office of Juvenile Justice and Delinquency Prevention conducted three longitudinal studies of high-risk, inner-city youth in Denver, Pittsburgh, and Rochester to identify causes and correlates of juvenile delinquency. In Denver, for example, about 3 percent of the sample of 1,527 youths were gang members in any given year during the 4-year study. Male gang members were more involved in delinquent activities than were nongang male counterparts. Gang membership lacked stability, with very few youths reporting being a gang member for more than a year. Other studies are reported that explored gang-related homicides in Chicago, gang migration, female gang participation, and gang involvement in drug trafficking and criminal activities. The author concludes that the violent youth gang problem is increasing. Recommendations for Federal action to deal with the gang problem are offered that focus on information collection and dissemination, coordination, program tests and demonstrations, training and technical assistance, and research. 51 references