The increasing diversity in classrooms throughout the U.S. calls for teachers who are culturally competent and have quality professional development in working with dual language learners (DLLs) in order to ensure children from diverse groups are receiving equitable and high-quality education. This study focuses on teacher characteristics that play a significant role in the development of young children's bilingual abilities with regard to language, literacy and math. We examined the school readiness skills of 217 Latino DLLs attending Head Start taking into account specific teacher characteristics that may impact the development of readiness skills. Different teacher characteristics have different effects on the developmental outcomes. Amount of training had a positive significant effect on several children's outcomes in English and in Spanish. The years of experience a teacher had working in classrooms with DLLs had a positive effect on children's English spelling skills. Teachers' cultural competency rating had a positive effect on receptive language and literacy in Spanish. Findings and implications are discussed.