The study of childhood diet, including breastfeeding and weaning, has important implications for infant mortality, early and later life health and fertility in past societies1. Nitrogen stable isotopic analyses of infant bone collagen and dentine have provided information on the timing and duration of weaning2, yet little is known of what foods were consumed by infants in prehistory. Possible infant feeding vessels, made from clay, first appear in Europe in the Neolithic, becoming more commonplace throughout the Bronze and Iron Ages. However, these vessels, complete with a spout, through which liquid could be poured, have also been suggested to be feeding vessels for the sick or infirmed3,4. Here, we report the first unequivocal evidence for the foods contained in such vessels based on lipid ‘fingerprints’ and the compound-specific δ13C and Δ13C values of the major fatty acids (FAs) from three small, spouted vessels found in Bronze and Iron Age infant graves in Bavaria. The results confirm the vessels were used for feeding ruminant milk products to infants, possibly mixed with small amounts of meat broth. This first direct evidence of the type of foodstuffs used either to feed or wean prehistoric infants confirms the importance of animal milk from domesticates for these early communities and provides the first direct information on infant feeding behaviours practised by prehistoric human groups.