"nObjective: The purpose of this study is to compare the executive functions children and adolescents who suffer from attention deficit hyperactivity disorder "n(ADHD) with normal children. "nMethod: Twenty children with ADHD were compared to 19 healthy children terms of some executive functions using the computerized version of Tower London, Continuous Performance Test (CPT), and Stroop Color Test. "nResults: In "Tower of London", the performance of children with ADHD was "nworse than normal children (p<0.05). In Continuous Performance Test, the "ncommission errors in children with ADHD were significantly more than the "nnormal group (p<0.01). In Stroop Test, the time spent to name the colors was "nsignificantly higher in ADHD group. A significant correlation was also found "nbetween the performance of children on Tower of London and CPT (P<0.05). "nConclusions: This study demonstrates that children and adolescents who "nsuffer from ADHD have some impairment of executive functions, particularly "nplanning and inhibition to response, but not in attention.