Studies of comprehensive school reform suggest that such efforts often fail because of educators' unwillingness to examine the root causes of underachievement and of failure among students from low-income and racially or ethnically diverse backgrounds and because of their tendency to locate the problem within students, families, and communities. Drawing on their research and professional development experiences, the authors present a conceptual framework for the deconstruction of deficit thinking through staff development. Next, they discuss assumptions and beliefs about culturally diverse students and families that they have encountered in low performing schools, and they illustrate how such beliefs may be successfully challenged and reframed.