This paper presents findings from a 4-year project that developed and implemented a blended inquiry science and English Language Development (ELD) program in a large urban California school district. The sample included over 2,000 students in Kindergarten through 5th grade. Participating students' English and science achievement was compared to a similar group of students who were using the district's established English language development curriculum. Student performance on state mandated English and science assessments were analyzed using Mann-Whitney U tests for overall performance and by number of years of treatment. Modest but statistically significant improvement was found for students who participated in the blended program. Results from this study suggest that restricting instructional minutes for science to provide additional time for ELD and English language arts may be unnecessary. Rather, allowing consistent time for science instruction that incorporates ELD instruction along with inquiry science experiences may provide the authentic and purposeful context students need to develop new language without restricting access to science content.