Professional development practices in schools have been changing recently, particularly with the mandates regarding professional development through No Child Left Behind. In 2001, the National Staff Development Council revised its standards of professional development to shift thinking in this area and reflect the changing needs of schools, students, faculty, and administrators. The purpose of this study is to provide an overview of a program based on the revised standards that acts as a catalyst for improving professional development practices at school sites, entitled Powerful Conversations in Professional Development, and to provide evaluation data that documents the program's effectiveness. Conversations were conducted at 32 school sites, selected to represent a variety of demographics. Approximately six months to one year after the conversations, depending on the cohort, surveys capturing professional development practices were sent to participating and comparison schools. In addition, participating schools were asked to revisit the self-assessment instruments to track change in practices over time. The following is a summary of the evaluation findings: (a) participating schools use more nontraditional practices that align with current standards of professional development than their comparison counterparts; (b) participating schools use more data-driven and research-based methods of professional development than their comparison counterparts; and (c) greater change in practices occurred over time, with the first cohort of schools making more significant gains in reforming professional development than the second cohort. (Contains 3 tables.)