Behavioral parent training (BPT) is an evidence-based intervention for the treatment of attention-deficit/hyperactivity disorder (ADHD) and related disruptive behavioral disorders of childhood. Despite convincing data on effectiveness, engagement to BPT, particularly for high-risk families, has been a long standing, yet understudied, issue. Data from a clinical trial of a comprehensive BPT approach to enhance engagement and outcomes (the Strategies to Enhance Positive Parenting [STEPP] program) are presented herein. The STEPP program was compared to a traditional group-based BPT program on propensity to attend treatment, propensity to complete homework over the course of treatment, and dropout from BPT. Additionally, factors empirically related to engagement to treatment and targeted by the STEPP program were analyzed to determine whether these factors were enhanced by participation in the STEPP program. In a randomized cohort of 80 single-mothers of school-age children with ADHD, analyses demonstrated that the STEPP program lead to greater propensity to attend treatment over time and a greater propensity to complete homework over the course of treatment. Furthermore, participation in the STEPP Program was associated with a lower rate of dropout. Finally, data suggested that parents assigned to the STEPP program reported significant improvements in factors empirically related to engagement that were targeted within the STEPP program (i.e., amount and quality of social support from their group members, expectations for treatment, and perceived barriers to treatment participation). Results of the study have implications for targeting engagement throughout the process of BPT, particularly for high-risk families. (Contains 2 tables and 1 figure.)