Purpose: The purpose of the current study was to examine the role that the 1st language, Spanish, at prekindergarten (pre-K) plays in predicting 2nd language (L2), English, word reading in 1st grade. In addition, it examines the role of conceptual vocabulary in predicting word reading in English. Method: As part of a longitudinal study of predictors and models of reading comprehension from pre-K to 3rd grade, 248 children attending preschool programs completed Spanish and English measures in the spring of each academic year. In this article, we report the results of English and Spanish measures of oral language and literacy skills that were administered in pre-K and 4 measures of English word reading that were administered in 1st grade. Results: Results from structural equation modeling indicated that Spanish oral language made significant direct and indirect contributions to English oral language and word reading. Further, results supported previous evidence indicating that L2 letter knowledge and L2 oral language proficiency are the strongest predictors of L2 word reading in 1st grade. Discussion: Similar to findings with monolingual English-speaking children, results support findings that, in the early stages of reading development, oral language in both 1st language and L2 make a significant and independent contribution to word reading. This study has important implications for the support of oral language skills in Latino preschool children. [Written with the Language and Reading Research Consortium (LARRC).]