The advent of Christianity in Nubia (modern Sudan) in the sixth century AD prompted a far-reaching cultural transformation, with changes in material culture, architecture, and cultural practice, marked in the funerary sphere as well. Due to its uneven hydrological conditions, Sudan has always been populated by peoples possessing diverse economic adaptations, with agricultural communities settled along the fertile Nile valley and various mobile pastoralist groups occupying vast areas of the adjacent deserts. This study contributes novel data to the study of medieval Nubian subsistence strategies through an assessment of stable carbon (delta C-13) and nitrogen (delta N-15) values in the bone collagen and apatite of 25 lay individuals interred within three contemporaneous cemeteries adjacent to the medieval monastic settlement of Ghazali in northern Sudan. Along with human values, this study utilizes a number of faunal samples for the comparative investigation of diet among various groups buried at the site. Collected results suggest primary reliance on C-4 products with regular contributions from terrestrial animal proteins. Examined in the context of archaeological data, large contributions of C-4 may be considered indicative of subsistence diversification and semi-pastoral economies of the local medieval populations.