Professional psychologists are increasingly encouraged to document and evaluate the quality of the treatment they provide. However, there is a significant gap in knowledge about the extent to which extant definitions of treatment quality converge with patient perceptions. The primary goal of this study was to examine how adolescent substance users (ASU) and their caregivers perceive treatment quality. The secondary goal was to determine how these perceptions align with expert-derived definitions of ASU treatment quality and dimensions of perceived quality used frequently in other service disciplines. Focus groups and individual interviews were conducted with 24 ASU and 29 caregivers to explore how participants conceptualize a quality treatment experience. Content analysis identified 3 major dimensions of perceived treatment quality, each of which contained 3 subdimensions: therapeutic relationship (i.e., acceptance, caring, connection), provider characteristics (i.e., experience, communication skills, accessibility), and treatment approach (i.e., integrated care, use of structure, and parent involvement). Results revealed modest convergence between patient perceptions and existing definitions of quality, with several meaningful discrepancies. Most notably, the therapeutic relationship was the most important dimension to ASU and their caregivers, while expert-derived definitions emphasized the treatment approach. Implications for practicing psychologists to enhance training and supervision, quality improvement, and health education initiatives are discussed.