The grey wolf Canis lupus has the largest geographical range of large mammalian carnivores in west Asia. However, it is one of the least studied species, particularly in Iran. Feeding ecology is a critical aspect of predator ecology and has important implications when formulating species and ecosystem management strategies. Also, predation on livestock is a crucial cause of wolf–human conflicts throughout the wolf's global range. Accordingly, we investigated the diet of the grey wolf in Ghamishlou, an area with high population densities of wild and domestic ungulates in central Iran, between July 2007 and April 2009. Scat analysis indicated that livestock was the single most important prey species for wolves with 47.1% of total biomass consumed, whereas Persian gazelle comprised 27.0% and wild sheep 15.9%. Wild kills were significantly skewed towards males relative to their proportion in the population, and were mainly preyed on during post-rutting months. Based on interview surveys, less than 1% of mean herd size was lost to wolf depredation; however, almost six times more died from non-depredation causes during each winter. We concluded that the high occurrence of livestock in the wolves' diet is mainly because of scavenging rather than depredation; however, owing to high pressure of wolves on local herds during non-winter seasons in other areas with depleted prey populations, local people dislike wolves and try to eradicate them. Finally, management implications are discussed and solutions are recommended.