We observed mother-child interactions, at baseline, in 136 families of 7-10-year-old boys with attention-deficit/hyperactivity disorder (ADHD) who were part of a large clinical trial, the Multimodal Treatment Study of Children with ADHD. Independent coders rated stylistic aspects of maternal behavior and factor analyses revealed a responsiveness factor that included overall responsiveness and sensitivity to the child, warmth and acceptance, and appropriate control. We examined relations between maternal responsiveness and (a) maternal depressive symptoms and maternal childhood ADHD symptoms, and (b) boys' ADHD and conduct problem symptoms. Controlling for all other variables, maternal responsiveness displayed a unique negative association with mother-reported child conduct problems, but not with child ADHD symptoms, and also was negatively related to maternal depressive symptoms. We discuss the unique association between mother-reported child conduct problems and parenting, and note the utility of studying parenting style in families of children with ADHD. We describe the results within the framework of a transactional model.