The current prospective study investigated transactional relations between maternal depressive symptoms and children's depressive and externalizing symptoms. Participants included 240 children (M age = 11.86 years, SD = 0.56; 53.9% female) and their mothers who were part of a 6-year longitudinal study. Measures of maternal depression (Beck Depression Inventory), child depression (Children's Depression Inventory), and children's externalizing symptoms (Youth Self-Report Form) were assessed annually. Data analyses using dynamic latent difference score structural equation models indicated that the observed relations between mothers' and adolescents' symptoms were stable across the 6 years. Higher levels of maternal depressive symptoms predicted subsequent elevations in children's depressive symptoms and in their externalizing problems over time. Among mothers with high initial levels of depression, children's depressive symptoms predicted subsequent declines in mothers' depressive symptoms. Children's externalizing problems were not related to subsequent change in maternal symptoms. (Contains 3 tables and 2 figures.)