This article provides analysis of a site-based professional development model that is grounded in teacher best practices. Developed by the administration and teacher leaders of a racially/ethnically, socioeconomically, linguistically and academically diverse school in the USA, the teacher-centered coaching model described is an example of an internal professional development program that aligns with research and involves exemplary best practices where the teachers are empowered to: identify the area of focus for growth; gather information about best practices related to the area of development; analyze and interpret the information gathered by research; facilitate training sessions on the topics of interest identified by the teachers; and engage all teaching faculty in study as a learning community. As indicated by analysis of a postprogram survey, this practice-based approach to the development of teachers enabled the improvement of their instructional methods and assisted in building knowledge that was useful beyond a particular reform program. A critical look at suggestions for improvement of the model based on international standards of best practice for professional development of teacher educators is also offered. IntroductionThis article begins with a review of the literature on sustaining teacher improvement regarding the latest revelations of teacher professional development. The phases of a model for teacher professional development designed by the administration and teacher leaders from a culturally diverse, high-risk and high-poverty school in the United States are then described. The model utilizes teacher coaches to implement a site-based professional development program and to promote inquiry amongst the staff. The results of a qualitative style survey administered to the participants at the school are analyzed and trends in responses are noted. Lastly, current research is shared to offer suggestions for improvement of the model to further promote sustainability and transferability.