Objective: This pilot study tests the feasibility and preliminary efficacy of an after-school treatment program for middle schoolers with ADHD using a randomized clinical trial design. Method: A total of 23 students with ADHD (25% female, 48% African American) from a large public middle school were randomly assigned to a 10-week program or to community comparison. Manualized treatment targeted educational, social, and recreational skills, homework completion, and school and home behavior. Parents participated. Results: Recruitment and randomization targets were easily met (87% completion). Parent and teacher satisfaction was positive. Small to medium treatment effects resulted despite greater medication use in the control group, with improvements in functioning for the program-treated youth or absence of deterioration relative to the comparison group. Conclusion: Despite testing an abbreviated version of the after-school program (less than 5 months), this study reveals feasibility and palatability for this intervention and modest beneficial effects on behavioral and academic outcomes. (Contains 3 tables.)