It is not known to what extent food insecurity may underlie the continued high rates of maternal to child transmission of HIV and AIDS (MTCT) in sub-Saharan Africa, where most cases of pediatric HIV and AIDS are reported to occur. However, a number of plausible conceptual models and a growing evidence base drawn from both qualitative and empirical studies suggest that food insecurity contributes significantly to the epidemic of pediatric HIV infection. Specifically, food insecurity puts women at risk of HIV infection and weakens the ability of infected women and the health systems to which they may have access to prevent secondary infection of their children. Applied anthropologists have played a role in understanding some of the pathways through which food insecurity mediates biological and social risks of maternal to child transmission of HIV and AIDS. Efforts to understand and address the biocultural pathways through which food insecurity increases transmission of HIV from mothers to children can raise awareness of the importance of food and nutrition security among policy makers and program planners. Applied research on food insecurity by anthropologists can inform communities and contribute to the design of improved programs to prevent of MTCT.