A meta-analysis of 63 peer-reviewed studies evaluated the ability of parent training programs to modify disruptive child behaviors and parental behavior and perceptions. This analysis extends previous work by directly comparing behavioral and nonbehavioral programs, evaluating follow-up effects, isolating dependent variables expressly targeted by parent training, and examining moderators. Effects immediately following treatment for behavioral and nonbehavioral programs were small to moderate. For nonbehavioral programs, insufficient studies precluded examining follow-up effects. For behavioral programs, follow-up effects were small in magnitude. Parent training was least effective for economically disadvantaged families; importantly, such families benefited significantly more from individually delivered parent training compared to group delivery. Including children in their own therapy, separate from parent training, did not enhance outcomes.