The present study aims to understand different factors that might affect Dual Language Learning (DLL) children's science scores. DLL children comprise one fifth of the children served by Head Start, however little is known about their science abilities. The domain of science has recently been recognized on a national level as an area of importance for early childhood education. Science is a key content area for DLL children because it provides opportunities to learn vocabulary, develop social-emotional skills, engage in critical thinking and problem solving. Despite the benefits that science education provides for young DLL children, few, if any studies have examined DLL children's science scores across languages. Additionally, there is a need to understand the effects of teacher language use during science instruction on Spanish/English DLL children's science outcomes. The current study examines the aforementioned in sample of teachers and children in Head Start centers across Miami-Dade County.