The food habits of Ammospermophilus leucurus were studied in southern Nevada. The contents of 609 stomachs were sorted into main food items such as seeds, green vegetation, arthropods and vertebrates. The per cent frequency of occurrence in the stomachs, and the per cent volume for each food item is given for monthly periods. In addition, data based on the contents of 154 cheek pouches and 93 observations of feeding behavior are given. These data indicate that this species is omnivorous. Food preferences appear to be closely related to food availability and to the need for some succulent food in the diet for the maintenance of water balance. Seeds are a staple throughout the year, strongly supplemented by green vegetation in the winter and spring and by insects in the summer and fall. Some vertebrate remains are found in stomachs throughout the year, and probably represent both prey and carrion. The highly generalized diet is discussed in relation to the large home range of the species and to the heterogeneity of the biotic community.