The purpose of the study was to evaluate the Homework, Organization, and Planning Skills (HOPS) intervention for middle school students with attention deficit hyperactivity disorder (ADHD) as implemented by school mental health (SMH) providers using a randomized trial design. Seventeen SMH providers from five school districts implemented the HOPS intervention. Forty-seven middle school students with ADHD (Grades 6-8) were randomly assigned to receive the HOPS intervention or to a waitlist comparison group. Parent and teacher ratings of organizational skills and homework problems were collected pre- and postintervention and at a 3-month follow-up; school grades were also collected. Intervention participants demonstrated significant improvements relative to the waitlist comparison across parent-rated organized action (d = 0.88), planning (d = 1.05), and homework completion behaviors (d = 0.85). Intervention participants did not make significant improvements relative to the comparison group according to teacher ratings. SMH providers were able to implement the HOPS intervention with fidelity despite the fact that no formal ongoing consultation was provided. (Contains 2 tables and 2 figures.)