This study explored two aspects of expanding the use of research-based practices in schools: (a) the extent to which mentor teachers could effectively teach a fellow teacher an instructional practice they had learned the previous year and (b) the extent to which the target practice would be implemented effectively by the partner after instruction from the mentor. Twelve teachers (11 third-grade, 1 second grade) from two schools participated in this study. Six teachers who acquired the target strategy the previous year served as mentors. Mentors were asked to teach, coach, model, and provide feedback to their fellow teachers on the target practice. Results demonstrated that mentors and most of their partners implemented the target strategies effectively and that all teachers reported levels of satisfaction with the practice much higher than with traditional professional development.