This chapter describes an intake questionnaire (Adquest) that was designed, tested, and implemented, and later employed in clinical data-mining studies, by practitioners in an adolescent mental health program. The instrument is primarily a practice-based, clinical information-gathering and client engagement device. The chapter describes Adquest and the practice-based priorities and decisions that determined its content and utilization. It illustrates some important differences between practice-based research (PBR) instruments such as Adquest and research-based practice (RBP) instruments such as RAIs. However, treating the PBR/RBP distinction as a continuum rather than as a dichotomy, the chapter goes on to describe our plan for aggregating and analyzing Adquest data in subsequent articles in this collection. The chapter offers evidence-informed insights into the risks, vulnerabilities and counseling needs of hundreds of urban youth seeking mental health services. Adquest explores multiple domains of adolescent functioning and focuses on issues of particular concern to inner-city adolescents.