Objective: There are few well-evaluated uncomplicated community-based interventions for childhood aggression. The authors assess the impact of a community-based anger management group on child aggressive behaviors, using a randomized, controlled trial (RCT). Method: Families with children 7 to 11 years old were recruited through advertisements and randomized (N = 123). Inclusion required parent concern about anger/aggressive behavior, RCT agreement, and a telephone behavior screen. Intervention participants were offered three parent psychoeducation/skill-building group sessions, 10 weekly child group sessions, and three in-home family practice sessions. Nine groups ran from August 2002 to August 2004. Interviewers naive to randomization collected data on all participants pre- and postgroup. Outcomes included child-rated anger and parent-rated child aggressive behavior, externalizing behavior and hostility, parent-child relationship, and parenting stress. Intent-to-treat analyses were done. Results: Pre/postoutcome comparisons indicated no significant differences between intervention versus control, with small effect sizes for most outcomes (0.27-0.29). Although not significant, the magnitude of improvement favored intervention families on all parent-rated measures. Conclusions: Overall, there was no differential impact of participating in a community-based anger management group versus control on child aggressive behaviors and other associated measures. The impact of regression to the mean, effect, and sample size estimates; child comorbidity; and programmatic and methodological issues are discussed. (Contains 1 figure and 3 tables.)