The San Gabriel Valley Science Project (SGVSP), is housed in the Center for Excellence in Mathematics and Science Teaching located in the College of Science at California State Polytechnic University, Pomona. The Project takes lessons learned from educational and scientific research regarding effective professional development to design programs for teachers in the context of their schools and districts. Guided by the California Content Standards and the English Language Development Standards, the SGVSP programs develop and enhance teachers’ instructional strategies and science understanding to improve the academic performance of their students, especially those for whom English is a second language.