Little is known regarding the extent to which aspects of the home language and literacy environment (HLE) promote growth in language skills among dual language learners (DLLs). Therefore, the purpose of this study was to evaluate which aspects of the HLE significantly predict growth in English and Spanish vocabulary among Spanish-speaking DLLs. 944 Spanish-speaking DLLs (51.6% female; mean age = 53.77 months) completed assessments of English and Spanish vocabulary at 4 time points across 2 academic years. Parents completed a survey of the HLE that included information on language exposure, reading exposure, and family reading habits. Results indicated that specific literacy-related practices, including availability of books in the home, language read to the child, and parental reading skills were significant predictors of growth in children's Spanish and English vocabulary knowledge, even after controlling children's initial level of language skills and family socioeconomic status. © 2021 Elsevier Inc.