The authors examined the impact of 2 subsequent, longitudinal interdisciplinary interventions for 58 Hispanic English language learners (ELLs): (a) Grade 5 science with English language/reading embedded (i.e., science intervention) and (b) K-3 English language/reading with science embedded (i.e., language/reading intervention). Results revealed that (a) in the science intervention treatment ELLs outperformed their counterparts in English-reading fluency, knowledge of word meaning, and science and reading achievement; (b) in the language/reading intervention treatment ELLs continued to develop faster than their peers in English oracy, reading fluency, and comprehension; (c) ELLs benefited more from the science intervention if they received the prior language/reading intervention. We conclude that for ELLs, the integration of science and English language/reading should primarily focus on reading in elementary grades and science in Grade 5.