Stable isotope analysis was performed on tooth enamel samples from more than 40 individuals from the Late Postclassic, Kaqchikel Maya capital of Iximché, Guatemala. Some of the associated skeletal remains exhibit damage associated with warfare and human sacrifice, including decapitation, suggesting that they were elite warriors or other war captives. The tooth enamel isotope data directly correlates diet and cranial trauma, and allows the identification of demographic groups within our burial sample. Tooth enamel isotope ratios also reflect the contribution of the whole diet, and complement an earlier bone collagen isotope study which suggested an extremely high dependence on maize.