One of our greatest educational challenges continues to be improving the education of English language learners (ELLs). Because many new teachers are underprepared and many veteran teachers wholly unprepared for teaching ELLs, school districts nationwide have initiated professional development programs for inservice teachers. In this article, the authors identify four programs showing particular promise and make recommendations for school systems seeking to enhance teacher knowledge of English language teaching. These four professional development programs have served to inspire more recent reforms in the professional development of English language development (ELD) teachers, and suggest that professional development for all ELD teachers must be comprehensive and systematic at all levels. Spotlight on Student Success is an occasional series of articles highlighting findings from the Laboratory for Student Success (LSS), the Mid-Atlantic Regional Educational Laboratory, that have significant implications for improving the academic success of students in the mid-Atlantic region.