Food insecurity is detrimental to child development, yet little is known about the combined influence of food insecurity and nutritional interventions on child development in low-income countries. We proposed that women assigned to an early invitation time to start a prenatal food supplementation program could reduce the negative influence of food insecurity on maternal-infant interaction. A cohort of 180 mother-infant dyads were studied (born between May and October 2003) from among 3267 in the randomized controlled trial Maternal Infant Nutritional Interventions Matlab, which was conducted in Matlab, Bangladesh. At 8 wk gestation, women were randomly assigned an invitation time to start receiving food supplements (2.5 MJ/d; 6 d/wk) either early (~9 wk gestation; early-invitation group) or at the usual start time (~20 wk gestation; usual-invitation group) for the government program. Maternal-infant interaction was observed in homes with the use of the Nursing Child Assessment Satellite Training Feeding Scale, and food-insecurity status was obtained from questionnaires completed when infants were 3.4-4.0 mo old. By using a general linear model for maternal-infant interaction, we found a significant interaction (P = 0.012) between invitation time to start a prenatal food supplementation program and food insecurity. Those in the usual-invitation group with higher food insecurity scores (i.e., more food insecure) had a lower quality of maternal-infant interaction, but this relationship was ameliorated among those in the early-invitation group. Food insecurity limits the ability of mothers and infants to interact well, but an early invitation time to start a prenatal food supplementation program can support mother-infant interaction among those who are food insecure.