The performance of 30 children with attention deficit disorder (ADD) was measured on a nonsense-word spelling task. The effects of two reinforcement schedules, partial and continuous, and 0.3 mg/kg methylphenidate were assessed. Children were assigned to one of three groups—no reinforcement, continuous reinforcement, and partial reinforcement. They performed the spelling task twice, once after ingesting 0.3 mg/kg methylphenidate and once following placebo ingestion. Results revealed that both reward conditions had large and equivalent beneficial effects on learning, as did methylphenidate. When reinforcement was combined with methylphenidate, performance was maximized. The results failed to support Douglas's (1983, 1985) hypothesis that partial reinforcement schedules have adverse effects on hyperactive children. The results also demonstrated the incremental value of the combination of methylphenidate and reinforcement in treatment of ADD.