This study examined the longitudinal link between clique membership status and the development of psychopathology in 451 children followed annually from age 9 to 12 years. Classroom clique membership status was identified through social network analysis, and internalizing and externalizing problems were assessed using peer nominations. Controlling for concurrent experiences of social preference and dyadic friendships, a high clique membership probability was found to be related to low levels of internalizing problems and to an increase in externalizing problems across 4 years. This link between clique membership and an increase in externalizing problems was found for boys only. (Contains 2 tables and 2 figures.)