This ERIC digest examines the growth and nature of juvenile gangs and the growing problem they present in the nation's public schools. It explores the characteristics of gangs, the impact gangs are having on public schools, why gangs develop and why students join them, what the schools' responses have been to gangs, and effective interactions for combating school gangs. The report reveals that gangs considerably differ in characteristics, numbers, and age ranges, but they all show strong loyalty to their neighborhoods. While gang participation is normally quite low among students, gang presence is still very disruptive to the ordinarily peaceful school atmosphere: fear, violence, drug use, and recruitment activities are common occurrences. Research shows that gangs catch hold in a school when students do not have a sense of belonging or acceptance in their lives, e.g., recent immigrants join gangs as a way to maintain a strong ethnic identity. Schools need a strategy that mobilizes school and community resources to offer alternatives to gang membership. Some intervention ideas include targeting vulnerable students and providing special assistance, establishing moral and ethical education, creating an environment where students feel valued, educating staff about how gangs develop and how to respond to them, and monitoring youth not enrolled in the school, i.e., those who hang out at, but do not attend, the school. Contains six references. (GLR)