English learners are faced with the dual challenge of acquiring English while learning academic content through the medium of the new language (Lee et al. in "J Res Sci Teach" 45(6):726-747, 2008; Stoddart et al. in "J Res Sci Teach" 39(8):664-687, 2002) and therefore need specific accommodations to achieve in both English and the content areas. Teachers require higher quality and new forms of professional development to learn and meet the needs of their students. This study examines the impact of one professional development model that explicitly embedded language learning strategies into science inquiry lessons. It also demonstrates how teachers involved in the PD program improve their self-efficacy about language instruction embedded in content and how they interpret and implement the methodology.