The present study examines the moderating role first grade classroom quality may have on the relations between children's difficult temperament (assessed in infancy) and their academic and social outcomes in early elementary school (first grade). Using data from the National Institute of Child Health and Human Development's Study of Early Child Care and Youth Development, 1032 children were rated by their mothers at 6 months of age on difficult temperament. The quality of first grade classroom environments were then observed and rated along three domains: emotional support, classroom organization, and instructional support. Regression analyses examined the statistical interactions between difficult temperament and classroom quality domains on children's academic and social outcomes. Results indicate high-quality classroom environments may ameliorate the academic and social risks associated with having a difficult temperament. (Contains 2 figures and 2 tables.)