Between 2005 and 2009, archaeologists excavated more than 100 skeletons from the medieval (1240s AD) Hungarian site of Solt-Tételhegy. Stable carbon and nitrogen isotope analyses were conducted on dental enamel and dentin from 24 individuals to examine their childhood diet. Although previous stable isotopic research has described the diet of medieval European peoples, this is the first such study on a medieval Hungarian population. The enamel ?13C values range from -14.4‰ to -8.6‰, with a mean of -11.1‰, while the dentin ?13C values range from -19.4‰ to -14.9‰, with an average of -17.4‰. These data indicate that C3 plants were the main plant type consumed by the majority of this population, with the exception of a few individuals, who appear to have included C4 plants in their diet. These results are to be expected, given the dominance of C3 over C4 plants in medieval Central Europe. Thus, based on historical and isotopic evidence, the outliers may have spent their childhoods elsewhere and later migrated into the Solt-Tételhegy area. The ?15N values range from 9.5‰ to 11.6‰, with a mean of 10.6‰, indicating that animal protein was prevalent in the diets of the sample population. Despite clear signs of status differences indicated by burial location, stable nitrogen values also point to relatively egalitarian access to animal protein amongst the individuals. The enamel ?18Op values range from 23.6‰ to 27.2‰, with an average of 25.1‰, suggesting that multiple migrations occurred into the study site. The results of this study show that the dietary and mobility information gleaned from stable isotope analysis can be used to interpret the lifeways of archaeological peoples. ?