The professional development school (PDS) is a model of choice for many teacher preparation programs. This approach integrates the functions of teacher preparation, professional development, inquiry and research, and student achievement to bring about whole-school improvement and the simultaneous renewal of the teaching profession. Ideally, inquiry and research serve as a catalyst for developing the PDS organization. However, a review of abstracts of purported PDS research (1988-2006) showed that most of the publications used nonresearch methods and focused primarily on descriptions of programs. In this article, we discuss issues surrounding the PDS that may account for the lack of development of a solid body of research about the phenomenon. We also propose a framework for research on PDSs that is aligned with the "Standards for Professional Development Schools" (National Council for Accreditation of Teacher Education, 2001) and with appropriate research methodologies recommended by the American Educational Research Association (Jaeger, 1998). (Contains 1 table.)