This article reports findings to promote the best practices of a transformative teaching and learning environment, from a case study of a yearlong full-immersion secondary-level professional development school. The results support the idea that interns have a significant stake, an active professional community commitment, and a heightened awareness during their training and before their employment. As a result of the full-immersion professional development school experience, interns experience a significant transformational impact in their personal and professional grounding as future career educators. Best practices for the promotion of authentic teacher preparation are discussed. (Contains 1 table.)