Attention-Deficit/Hyperactivity Disorder (ADHD) is a commonpsychiatric disorder that has reliable association with impairment ofExecutive Functions (EFs). Also both Oppositional Defiant Disorder(ODD) and Conduct Disorder (CD) are associated with poorneurocognitive performance, in this study we assessed EFs in childrensuffering from ADHD with co- morbid ODD/ CD in comparison withchildren suffering from ADHD without comorbidity of either ODD/ CD,and both groups were compared with control group. They werediagnosed by the kiddie-Schedule for Affective Disorder andSchizophrenia-Present and Lifetime Version (K-SADS-Pl) and accordingto DSM-IV criteria, then Behavior Rating Inventory of ExecutiveFunction (BRIEF), parent form questionnaire was given to their parentsto assess for magnitude of impairment in EFs while children weresubjected to subtests of Wechsler Intelligence Scale for Children (WISC)for assessing certain EFs. We found that children suffering from ADHDwith or without co- morbid ODD/ CD showed significant impairment inEFs when compared with control group and that children suffering fromADHD with co-morbid ODD/CD showed poorer performance in EFsthan children suffering from ADHD alone.