Using data from three waves of a large Canadian data set, we examine the relationship between two middle childhood trajectory variables, family dysfunction and anxiety. We draw upon family systems theory and developmental psychopathology, while attempting to expand their boundaries by capitalizing on the strengths within both approaches. Our data treatment strategy, guided by the life course analytical framework, included separate multivariate logits to examine this relationship, with and without the extent to, which selected explanatory risk variables predicted belonging to the highest family dysfunction trajectory. We also explored possible interactions between anxiety and explanatory risk variables. Supporting our hypothesis, a prolonged duration of high doses of family dysfunction was associated with the most extreme developmental trajectories of anxious behavior during middle childhood for both boys and girls. This relationship prevailed above and beyond the influence of other correlates of family dysfunction such as marital transition, socioeconomic status, family size, and depressive symptoms experienced by the informant (mostly mothers).