The diet of "Gigantoraptor" is uncertain. Although some oviraptorosaurs such as "Caudipteryx" and "Incisivosaurus" are thought to have been mostly herbivorous, "Gigantoraptor" had long hind legs with proportions that allowed for fast movement, and large claws, a combination that is not usually found in herbivores of this size. Paul suggested that "Gigantoraptor" also was a herbivore and used its speed to escape predators.