Possible mediators of the relation between maternal depressive symptomatology and parenting behavior were examined for 96 children with ADHD and their mothers drawn from the Multimodal Treatment Study of Children with ADHD (MTA) as part of an add-on investigation conducted by two of the six MTA sites. General cognitions (i.e., maternal locus of control and self-esteem) and parenting-specific factors (i.e., maternal parenting efficacy and parenting stress) were examined as possible mediators. Findings provide initial support that maternal parenting stress, as well as maternal locus of control and self-esteem mediate the relation between maternal depressive symptomatology and parenting behavior. This provides support for the argument that some families of children with ADHD may benefit from an expanded version of parent management training that includes sessions directly targeting affective and cognitive factors in parents, similar to treatment programs used to treat childhood conduct problems.