Current knowledge of infant feeding and weaning practices during the Roman period in Egypt is limited to scanty documentary and iconographic evidence. Stable nitrogen and carbon isotope analysis provides another avenue to explore this question. A sample of 49 infant and juvenile human skeletal remains from the Kellis 2 cemetery in the Dakhleh Oasis, Egypt, was used to determine patterns of infant feeding and weaning. δ15N values indicate that supplementary foods were introduced at around 6 months of age, and that weaning was complete by 3 years of age. By 6 months of age, δ13C values become increasingly enriched over adult values, and reach peak enrichment at approximately 1.5 years of age. Beyond this age, δ13C gradually declines to approach adult values. This enrichment in infant δ13C values is indicative of consumption of 13C-enriched supplementary foods. Based on isotopic study of faunal and botanical remains from the ancient village of Kellis, we conclude that at approximately 6 months of age, infants were fed milk of goat and/or cow. Am J Phys Anthropol 115:204–212, 2001. © 2001 Wiley-Liss, Inc.