Harsh parenting behaviors are alarmingly prevalent during infancy and toddlerhood. From an ecological perspective, predicting and preventing harsh parenting requires probing not only micro- and exosystem-level processes but also the interactions among them. In the current longitudinal study, we examined associations among maternal depressive symptoms, harsh parenting, and neighborhood collective efficacy in 142 low-income Latina mothers and their infants (M
child age = 14.11 months, SD = 3.60). We hypothesized that there would be a mediated pathway from maternal depressive symptoms to harsh parenting to toddler behavior problems, and that neighborhood collective efficacy would moderate this pathway. As predicted, maternal depressive symptoms predicted toddler behavior problems, and harsh parenting significantly mediated this association. Moreover, neighborhood collective efficacy was a significant moderator such that this indirect pathway was maintained in the context of low neighborhood collective efficacy only. When collective efficacy was high, this pathway was not significant. Results are discussed in terms of the buffering potential of neighborhood collective efficacy. Tentative implications for leveraging neighborhood supports to prevent early harsh parenting are suggested.