Objective: This study examined the feasibility and effectiveness of a behavioral parent training (BPT) group intervention implemented in an outpatient mental health setting in reducing child impairments and increasing parenting confidence in managing child behavior. Method: Parents of 241 children with ADHD participated in the eight-session parent group program, completing the Impairment Rating Scale (IRS) and a measure of parenting confidence at the first and last session. Results: Parents reported improvements in child behavior across all domains of the IRS, with the largest improvements in terms of overall impairment, parent–child relationship, and impact of child behavior on the family. Parents also reported increased confidence in managing their child’s behavior. Conclusion: These findings suggest that brief BPT group programs administered to a diverse range of attendees in a typical outpatient setting result in improvements in functional impairments comparable with those produced in controlled studies, as well as improved parenting confidence. (J. of Att. Dis. 2013; XX(X) 1-XX)