Objective: Few studies have examined the psychological benefits of physical activity in children with ADHD who may be at higher risk for mood and anxiety problems. This study explores the relationship between participation in physical activity and emotional functioning in children with ADHD. Method: Scores on parent-reported measures of mood and behavior were retrospectively compared among a group of 65 children (ages 6 to 14) diagnosed with ADHD based on their amount of sport participation. A total of 32 children diagnosed with a learning disorder (LD) were used as a comparison group. Results: Children with ADHD who participated in three or more sports displayed significantly fewer anxiety or depression symptoms than did those who participated in fewer than three sports. These differences were not evident among children with LDs. Conclusion: Results suggest that active sport participation may be associated with a reduced expression of anxiety or depression symptoms in children with ADHD. (Contains 3 tables and 2 figures.)