We investigated the longitudinal associations among maternal pre- and postnatal depression, maternal anxiety, and children's language and cognitive development followed from 15 to 61 months. Furthermore, we assessed the protective role of children's early print experiences with books against the adverse effect of maternal depression on language development. Data for mothers and children (51.7% boys, 95% White, N = 11,662) were from the Avon Longitudinal Study of Parents and Children. Prenatal maternal depression held an adverse association with child language ([beta] = -0.16, p = 0.002). Moreover, the risk was greater for girls than boys ([beta] = 0.19, p = 0.02). In addition, prenatal depression was significantly and negatively associated with child verbal intelligence quotient ([beta] = -0.11, p = 0.02) and performance intelligence quotient ([beta] = -0.12, p = 0.01). In contrast, postnatal depression or anxiety were not unique predictors of child outcomes. Importantly, children's early experiences with books, as measured by the reported frequency of parent-child shared reading, moderated the negative association between maternal depression and child language development ([beta] = 0.30, p < 0.001). Although modest in size, these findings inform models of child risk and resilience related to maternal psychopathology. The results also have implications for clinical programs as well as for prevention and intervention studies focusing on at-home early literacy.