Although the education sector has been referred to as the "de facto" mental health system for children and adolescents, such statements obscure the tremendous heterogeneity of school-based mental health (SMH) initiatives. This study asked how different school contexts and SMH provider types may influence different aspects of SMH service delivery. Data are derived from results of evaluations of implementation and outcomes of a research-based practice model (the Brief Intervention for School Clinicians [BRISC]) tested in two common but quite different SMH contexts. In one context, BRISC was implemented in a large urban school district by externally employed practitioners working in schools (n = 5); in the second context, BRISC was implemented across a large Canadian province by school-employed mental health practitioners (n = 24). Results suggest that certain variables showed small differences across contexts, including intervention adherence, and perceived relevance, acceptability, and feasibility of BRISC. Other variables varied much more substantively, such as baseline seriousness of mental health needs, rate of out referral of students to alternative community-based services, and student mental health outcomes. Although exploratory, the current study focuses a useful lens on practice patterns across SMH contexts in secondary schools and underscores the importance of considering contextual factors early in an implementation process.