This article examines the influence of gang organization on several behavioral measures. Using interview data from juvenile detention facilities in three Arizona sites, this article examines the relationship between gang organizational structure and involvement in violent crime, drug sales, victimization, and arrest. The gang literature suggests that gangs are not very well organized. However, the findings from the current research suggest that even low levels of gang organization are important for their influence on behavior. Indeed, even incremental increases in gang organization are related to increased involvement in offending and victimization. (Contains 3 tables and 8 notes.)