Abstract: The California Foreign Language Project (CFLP), established in 1988 by the California legislature, is a professional development program designed to improve and expand foreign language teaching in California while promoting access and equity within educational institutions for every student. As one of the nine content areas of the California Subject Matter Project, CFLP is a voluntary project that served 609 elementary, secondary, and postsecondary foreign language teachers from 43 counties in 1998/1999. This article describes the origin and rationale of the California Foreign Language Project and discusses the importance of professional development programs, a topic of growing interest given the nationwide focus on student performance and school reform. Finally, the components of professional development program evaluation, and specifically of CFLP's Evaluation Design, will be presented, along with the findings from the 1998/1999 program year.