The associations between children's academic reputations among peers and their academic self-concept, effort, and performance were examined in a longitudinal study of 427 students initially enrolled in Grades 3, 4, and 5. Assessments were completed in the fall and spring of 2 consecutive school years and in the fall of a 3rd school year. Peer academic reputation (PAR) correlated moderately strongly with teacher-rated skills and changed over time as a function of grades earned at the prior assessment. Path-analytic models indicated bidirectional associations between PAR and academic self-concept, teacher-rated academic effort, and grade point average. There was little evidence that changes in self-concept mediated the association between PAR and effort and GPA or that changes in effort mediated the association between PAR and GPA. Results suggest that peers may possess unique information about classmates' academic functioning, that children's PARs are psychologically meaningful, and that these reputations may serve as a useful marker of processes that forecast future academic engagement and performance. (Contains 5 tables and 2 figures.)