Objective: It has been reported that Oppositional Defiant Disorder (ODD) can be differentiated into distinct subtypes associated with different outcomes in adulthood. We examined whether ODD is conceptually independent and coherent, and whether ODD and Conduct Disorder (CD) are expressions of the same core deficit. Method: The data come from a sample of 4,380 children for whom SNAP rating scales were available. Parallel analysis was performed on the eight-item ODD diagnostic items and on the SNAP-90 scale. These were factor analyzed and the components were correlated. Results: ODD has one underlying factor, whereas the parent-rated SNAP has nine underlying factors. ODD items grouped together with emotional lability and irritability items, which did not group with CD. Confirmatory factor analysis supported the separation of ODD and CD but not ODD and emotion dysregulation. Conclusion: The expanded ODD factor more likely captures a disorder of emotion regulation, rather than a disruptive behavior disorder. (J. of Att. Dis. 2013; XX(X) 1-XX)