This study investigates the contribution of the home language environment of Latino children of immigrants (N= 228) and their Spanish and English proficiency in relation to their social and emotional well-being. Multiple regressions evidenced that home language use and literacy practices accounted for significant variance in children's Spanish and English proficiency at kindergarten. Likewise, the home language environment and Spanish and English proficiency had a unique and significant contribution towards variance in children's social and emotional well-being as reported by teachers. These findings underscore the important role of children's dual language abilities in their adaptation at school. These associations will be further discussed as well as specific dimensions of social and emotional well-being in relation to school functioning.