There is growing interest in yoga to enhance positive youth development, but many challenges to overcome before introducing yoga to schools. Weisz et al. [Weisz, J. R., Jensen, A. L., McLeod, B. D. (2004). "Development and dissemination of child and adolescent therapies: milestones, methods, and a new deployment-focussed model." In E. D., Hibbs & P. S. Jensen (Ed.), "Psychosocial treatments for child and adolescent disorders: Empirically-based approaches" (2nd ed.). Washington, DC: American Psychological Association] describe the multi-phased deployment focused treatment development model (DFM) as a means of overcoming barriers to implementing evidence-based interventions. Consistent with the first phase of the DFM, which involves manual development with input from stakeholders, we describe teachers' reactions to implementation of school-wide yoga in an urban elementary school. In keeping with the second phase of DFM, we conducted a pilot efficacy study of a yoga curriculum. We got mixed results on academic performance, and no effect on behavior and attendance. This is first study we know of that systematically collected teacher data about yoga and used school grades and standardized test scores as outcome measures. Teacher involvement, retention of students, fidelity and documentation of treatment delivered, and efficacy for grades, attendance, and behavior are paramount considerations for future school-based yoga studies.