This study sought to examine sustained, school-based professional development (PD) on explicit reading comprehension strategy instruction (ERCSI) and its influence on teacher knowledge and practice and on student outcomes. Eight teachers participated - four first-grade and two teachers each from second and third grade. At the beginning of the school year, the teachers in this study scored less than 50% on an assessment of the declarative, procedural, and conditional knowledge of the strategies they were to teach. Through sustained PD that provided a six-lesson framework for explicitly teaching reading comprehension strategies and observations with feedback, the teachers scored higher with regards to knowledge about the comprehension strategies they were teaching. Teachers felt the PD changed their teaching, and they noted changes in their students' reading behaviors.