Objective: Attention deficit hyperactivity disorder (ADHD) is a chronic, highly prevalent neurodevelopmental disorder which affects 9% of school-age children. Triple P-positive parenting program is an evidence-based parenting program reported to be useful in the management of this disorder. The aim of this randomized controlled trial was to evaluate the effectiveness of Triple P in mothers of ADHD children.Methods: In this study, 30 mothers with ADHD children aged between 6 to 10 were randomly assigned to two groups (15 participants in each group). parenting style, mother-child relationship, maternal depression, anxiety and stress, and children’s behavioral problems were evaluated. The intervention group received 120 minute sessions for 5 weeks and 15-30 minute telephone contacts for 3 weeks while no intervention was done for the control group.Results: Analysis of covariance revealed that mothers of the Triple P group showed significant (p<0.01) improvements in parenting style, mother-child relationship, and considerable decrease in depression, anxiety and stress. Women trained in the Triple P group also reported significantly lower rates of child misbehavior than women of the control group.Conclusion: Triple P-positive parenting intervention is effective and acceptable for mothers of ADHD children.