This study examined ethnic and sex differences in children's depressive symptoms, along with hypothesized mediators of those differences (academic achievement, peer acceptance), in a follow-up of African American (n = 179) and Euro-American (n= 462) children in Grades 3 to 5. African American boys reported more depressive symptoms than African American girls, and Euro-American boys and girls. Also, depressive symptoms of African American boys increased over time whereas depressive symptoms of the other groups decreased or remained stable. Academic and social competence deficits were associated with elevated levels of depressive symptoms across the school year, although only academic achievement scores emerged as a unique predictor of increases in depressive symptoms over time. Neither academic nor social competence mediated the Sex[Acirc] x [Acirc] ethnicity interaction in changes in children's depressive symptoms.