This study examined associations between quality of social and physical environments in preschools and children's development of academic, language, and literacy skills, and the extent to which preschool quality moderated the associations between child risk and development. Participants were a diverse sample of 540 four-year-old children in Georgia who attended Head Start, the Georgia Pre-Kindergarten Program, or private preschools. Controlling for children's gender, family income, race/ethnicity, preschool program type, and pretest performance, high-quality social environments were positively associated with children's academic and literacy skills at the end of preschool. Quality of the physical environment was not associated with children's outcomes at the end of preschool; however, higher quality physical environments moderated the negative associations between income and academic development and between non-White race/ethnicity and literacy development. (Contains 5 tables and 2 figures.)