Ruminative thinking has been identified as a vulnerability factor for the onset and maintenance of depression. Furthermore, depressed persons who are high in rumination report more difficulties in intimate relationships. It is still unclear, however, whether rumination is predictive of postpartum depressive symptoms as well as impairments in the mother–infant relationship. Possible associations were investigated in a short-term longitudinal study. Controlling for age, pre- and postnatal depressive symptoms, ruminative thinking during pregnancy was a significant predictor of mother-reported impairments in the mother–infant relationship. Yet, rumination was not predictive of postpartum depressive symptoms. The implications of these findings are discussed.