This paper evaluates a large-scale maternal cash transfer program targeted to pregnant women and mothers of children under two. The program provides monthly cash transfers, and is supplemented with Social Behavior Change Communication (SBCC) in a random subset of villages. Both interventions lead to a large reduction in the proportion of children (moderately) stunted. Meanwhile, cash alone has no detectable impact on child outcomes. The effects are accompanied by improvements in dietary diversity, breastfeeding, hand-washing practices, prenatal care and food consumption. These results provide strong support for adding SBCC to maternal cash transfer programs in order to realize their impact.