The association of pubertal maturation with internalizing and externalizing symptoms was examined with a sample of 867 African-American 10-12-year-old children. Children reported their pubertal development status and timing using a self-report questionnaire, and symptoms were assessed through diagnostic interviews with the children and their primary caregivers. Pubertal status and timing were significantly associated with children's reports of the internalizing symptoms of social anxiety disorder, generalized anxiety disorder, and major depression and with the externalizing symptoms of oppositional defiant disorder, attention deficit disorder, and conduct disorder. Pubertal development also was associated with caregivers' reports of children's externalizing symptoms. The pubertal transition was associated with internalizing and externalizing symptoms in both boys and girls.