Developing teachers for leadership is an important step needed to build strong instructional programs in our schools. As a method for developing leadership, project-based learning (PBL) has incredible potential. The project used in this study asked in-service teachers (ISTs) taking a graduate level mathematics education course to develop and lead an all-day professional development session for local schoolteachers designed to improve learning in the district. The project provided an authentic experience in which ISTs engaged in the practice of leadership. Responses from the ISTs who led the PD indicated that the experience helped them create a vision of themselves as leaders. Furthermore, the opportunity to receive feedback from the instructor and their classmates, coupled with time for reflection and revision, proved to be significant in helping ISTs take on their new identity.