Abstract Background and Objectives: Despite efficacious treatments and evidence-based guidelines, youth coping with attention deficit hyperactivity disorder (ADHD) receive suboptimal care. Primary care clinicians (PCCs) are frontline providers of ADHD care; however, little is known about PCC perspectives regarding this care gap and how to effectively address it within health systems. We investigated PCC perspectives on determinants of pediatric ADHD care and considerations for improving adherence to evidence-based guidelines. Methods: Semi-structured qualitative interviews were conducted with 26 PCCs representing clinics within a health system on improving adherence to treatment guidelines for pediatric ADHD. Interview guides were based on the Pragmatic Robust Implementation and Sustainability Model (PRISM) to elicit PCC views regarding determinants of current practices and suggestions to guide improvement efforts. We used thematic analysis to identify patterns of responding that were common across participants.Results: We identified 12 themes categorized into two broad domains: Status Quo of Pediatric ADHD Care and Supporting and Constraining Factors for Improvement Initiatives. PCCs identified several internal and external contextual factors as determinants of current practices. Of note, PCCs reported they face challenges at multiple steps in the care process, including mental health stigma, coordinating care across settings, clinical productivity pressures, access to behavioral health care, and insurance mandates regarding medications. PCCs recommended efficient continuing education trainings accompanied by improvements to the electronic health record to include validated screening tools and documentation templates.Conclusions: Future research triangulating these findings may help to more efficiently improve the quality of pediatric ADHD care in health systems.