The hypothesis that measures of sub-adult mortality rates in natural fertility populations are associated with subsistence practices in a selected cross-cultural sample (n=39) was tested. After controlling for both distance from the equator and the general likelihood of cultural similarities between genetically closely related cultures using phylogenetic comparative methods, it was found that dependence on extractive modes of subsistence (hunting, gathering and fishing) was a significant positive correlate of total child mortality (15q0). Both increases in dependence on foraging and permanent settlement were associated with increases in child mortality between pairs of historically related cultures. The results indicated little association between infant mortality (1q0) and either dependence on foraging or settlement.