The integrated school library program model advocated by school library professionals and described in government policy and library association position papers is an innovation that has been difficult to implement in North American schools. The model proposes that the primary role of the school library professional is teaching in partnership with classroom teachers. The librarian collaborates with classroom teachers and others to plan, teach, and assess critical information literacy skills and strategies integrated with curriculum content. Because elements of the integrated school library program challenge the traditional culture of the school, the school library professional often needs to work as a change agent. Changing the organizational culture of the school constitutes the key role and goal for the school library professional and requires a deep knowledge of the particular culture of the school and the complexities of the change process. Although the school as an organization has been buffeted by changes in the past half-century, some features of schools remain highly resistant to change. In concert with developing an integrated school library program, the school library professional can also be involved in implementing other specific instructional innovations or responding to broader school reform initiatives. The key concepts of organizational culture and change have important implications for school library professionals, educators, and researchers.