Abstract The present study reports the results of a prospective, 8–year follow-up study of 100 hyperactive and 60 normal children followed from childhood into adolescence. Ratings of child behavior problems and family conflicts as well as direct observations of mother-child interactions were taken in childhood and again at adolescent follow-up. At outcome, hyperactives continued to have more conduct and learning problems and to be more hyperactive, inattentive, and impulsive than controls. Hyperactives were also rated by their mothers as having more numerous and intense family conflicts than the normal controls, although the adolescents in both groups did not differ in their own ratings of these conflicts. Observations of mother-adolescent interactions at outcome found the hyperactive dyads displaying more negative and controlling behaviors and less positive and facilitating behaviors towards each other than in the normal dyads. These interaction patterns were significantly related to similar patterns in mother-child interactions observed 8 years earlier. Mothers of hyperactives also reported more personal psychological distress than normal mothers at outcome. Further analyses of subgroups of hyperactives at outcome, formed on the presence or absence of ADHD and oppositional defiant disorder (ODD), indicated that the presence of ODD accounted for most of the differences between hyperactives and normals on the interaction measures, ratings of home conflicts, and ratings of maternal psychological distress. Results suggest that the development and maintenance of ODD into adolescence in hyperactive children is strongly associated with aggression and negative parent-child interactions in childhood.