This study examined teacher empowerment through the development of individual and collective teacher efficacy. A content-centered staff development program implemented in a Michigan school district by the New Zealand Ministry of Education and Oakland University helped teachers develop efficacy in the teaching of mathematics and in the ability to design and implement student-centered instruction. Participants--including teachers, administrators, and teacher development personnel--were interviewed extensively, and the results were analyzed to ascertain if a content-centered staff development program helped teachers become more confident in their teaching abilities and in their willingness to take an active role in helping other teachers implement instructional programs. This research can benefit superintendents and principals who are considering creating and implementing such staff development programs.