Attention deficit/hyperactivity disorder (ADHD) is a chronic disorder characterized by developmentally inappropriate levels of inattention, impulsivity and overactivity. The symptoms of ADHD result in serious impairment in many domains of functioning. The proposed program of research seeks to expand the treatment outcome literature on behavioral and treatment in the community to be used with an underserved population - the fathers of ADHD children. To this end, the format of an evidence-based behavioral treatment for ADHD, behavioral parent training, has been modified to increase father participation, engagement, and satisfaction with treatment and therefore improve outcomes. This novel parent training format will be investigated and compared to traditional parent training programs and a waitlist control in a randomized, controlled clinical trial, in order to begin an investigation of the most efficacious means of engaging and retaining the fathers of children with ADHD in treatment.