The developmental significance of children's academic reputation among peers was examined in a longitudinal study of 400 children in Grades 3, 4, and 5. In the fall of Year 1, teachers rated children's academic skills and behavior, and peers provided nominations describing classmates' academic skills, social acceptance versus rejection, and aggressive behavior. In the fall and spring of Year 1, children provided reports of their academic self-concept, social self-concept, and global self-worth. In the fall of Year 2, teachers rated children's academic skills. Results indicated that 4 items assessing peer academic reputation formed an internally consistent scale that was correlated moderately and distinctively with teacher-rated academic skills. Peer academic reputation and teacher-rated academic skills each contributed independently to the prediction of fall-to-spring changes in children's academic self-concept. Peer academic reputation and academic self-concept contributed uniquely to the prediction of changes in teacher-rated academic effort and skills over a 1-year period.