Objective: The objective of this study was to compare the social functioning of children with the Combined (CB) and Predominantly Inattentive (PI) subtypes of Attention Deficit/Hyperactivity Disorder (ADHD), controlling for comorbidity and medication-status, which may have confounded the results of previous research. Method: Parents and teachers of rigorously diagnosed unmedicated children with PI or CB subtypes of ADHD, and typical comparison children, rated them on the multidimensional Social Skills Rating Scale (SSRS). Results: After co-varying for oppositionality and anxiety, social impairment was substantial and equivalent in both ADHD groups whether rated by parent or teacher. In addition, when rated by teacher, the nature of the deficits varied by subtype: Children with PI were impaired in assertiveness, whereas children with CB were deficient in self-control. These findings indicate that AD/HD subtypes differ in the nature of their social dysfunction independent of comorbidity and highlight the need for interventions to target their divergent needs. (Contains 3 tables.)