Abstract Attention-deficit/hyperactivity (ADHD) disorder is one of the most prevalent mental health conditions among youth and the majority are cared for in primary care. Prior work indicates that youth with ADHD have poorer functioning than youth without ADHD. The Institute of Medicine emphasizes the importance of family engagement during visits. Simple interventions that are easy to implement are needed to engage youth and parents more during ADHD pediatric visits. We were one of the first research teams to use question prompt lists with youth. We found that a youth asthma question prompt list/video intervention significantly increased youth question-asking and provider education. We also found that youth who received the intervention and asked their providers questions were significantly more likely to have improved asthma control at 12 months. We propose to test having both youth and parents receive an ADHD question prompt list and watch a short video on the importance of being involved in ADHD visits. The rationale for having prompt lists for both youth and parents is that in contrast to asthma visits where parents tended to ask questions and youth did not, in our prior ADHD work, very few youth or parents asked questions. Yet, youth reported having an average of 8 questions about ADHD and parents an average of 8.9 questions. Using Social Cognitive Theory as a guide, we propose to conduct a pilot randomized controlled feasibility trial of the intervention. We will enroll 140 English- speaking youth ages 11-17 with an ADHD medical record diagnosis who screen as having predominantly inattentive subtype, hyperactive/impulsive subtype, or combined inattention/hyperactivity on the Vanderbilt assessment scale from three pediatric clinics. We will randomize the families to receive both the question prompt lists and video (N=35), just the question prompt lists (N=35), just the video (N=35), or usual care (N=35). This will allow us to understand whether both the video and question prompt list parts are needed in the larger trial. The aims of our trial will be: (1) To examine whether the ADHD question prompt lists and/or pre- visit video significantly impact the proposed mechanisms of the intervention. We will investigate whether adolescents and parents in each of the intervention groups: (a) ask more questions and receive more provider education about ADHD during their baseline and 3 month visits and (b) have higher self-efficacy at 3 and 6 months than adolescents and parents in the usual care group. (2) To investigate the effectiveness of the ADHD question prompt lists and/or the pre-visit video by examining whether adolescents in each of the intervention groups have improved ADHD symptoms, school and social performance, and quality-of-life at 6 months compared to those in the usual care group. (3) Assess adolescent, parent, and provider feedback on the acceptability, feasibility, tolerability, and safety of using the ADHD question prompt lists and/...