Here, we present δ13C and δ15N results for the dietary reconstruction of nomadic pastoralists from the Iron Age (ca. 1000 bc–8 ad) site of Heigouliang. The human (n = 27) δ13C values range from −19.6‰ to −17.0‰ with a mean value of −18.5 ± 0.5‰, and the δ15N results range from 11.5‰ to 13.8‰ with a mean value of 12.4 ± 0.6‰. The results indicated that animals, like sheep, were part of the predominately C3 terrestrial diet, but two individuals have values greater than −18‰ that is indicative of some input of C4 foods in their diets. Because of a lack of faunal samples and to supply complementary information concerning plant consumption, teeth from four individuals were analysed for dental calculus microfossils. Starch grains were found to correspond to Triticeae and Poaceae, possibly including wheat (Triticum aestivum), barley (Hordeum vulgare), highland barley (H. vulgare L var. nudum), foxtail millet (Setaria italica) and/or common millet (Panicum miliaceum). At the population level, no dietary differences were detected between burial owners and sacrificial victims, but variations were found when specific tombs were analysed. In particular, individuals with bone trauma associated with armed conflict also had distinct isotopic signatures possibly suggesting that some of the sacrificial victims could have been captured warriors that were sacrificed for the burial owners. While limited, the results are some of the first from an Iron Age population from Xinjiang and contribute to our understanding of the dietary patterns of this region. Copyright © 2015 John Wiley & Sons, Ltd.