Very little work has examined potential moderating effects in the link between prenatal intimate partner violence (IPV) and infant adjustment, especially in the first critical weeks following delivery. The current study evaluated the protective role of breastfeeding in the relationship between prenatal IPV and infant temperament at 4 months. Pregnant women (n = 82) were interviewed during pregnancy and at 6 weeks and 4 months postpartum. It was hypothesized that (a) prenatal IPV would predict infant temperament outcomes at the 4-month postpartum visit, and (b) breastfeeding continuation at 6 weeks acts as a protective factor such that breastfed infants will be less affected by the risk posed by prenatal IPV. Results indicated direct and negative effects of prenatal IPV on positive affectivity/surgency and orienting/regulatory capacity at 4 months. A significant moderating effect of breastfeeding at 6 weeks postpartum was identified. Mothers who were not breastfeeding at 6 weeks postpartum demonstrated the expected negative relationship between prenatal IPV exposure and infant adjustment, but if mothers were breastfeeding at 6 weeks postpartum, the relationship between IPV exposure and infant positive affectivity/surgency and orienting/regulatory capacity was not significantly different from zero. Results indicate a significant protective effect of breastfeeding in the intergenerational transmission of risk for infants born to mothers exposed to IPV.