This Evaluation Brief examines the BSCS approach to improving secondary science education, and illuminates some of the lessons learned from its five years of work with districts across the nation. It highlights selected findings from the full study report and discusses the broader implications for the field. Specifically, this Brief examines the success of the National Academy for Curriculum Leadership (NACL) teams; lessons learned about factors that shape the effectiveness of NACL teams; lessons learned about using curriculum as a leading edge for change; and lessons learned about improving high school science education.