In this year-long randomized control trial (RCT), we evaluated the effectiveness of a year-long, intensive, and structured virtual professional development (VPD) accompanying science-integrated English-as-second-language (ESL) instructional intervention on 187 second grade English learners' English language and literacy development in suburban school district in Texas. Multilevel modeling approach revealed that the intervention effect was positive and significant, reflecting a range of expressive oral vocabulary, decoding skills, and content reading, indicating the effectiveness of this intervention. We conclude that more well-planned, scientifically-based research in school is needed to promote the English language and literacy development and content area learning of English learners. This study also highlighted the importance of fidelity of implementation for research in school.