The condition and age of Thomson's gazelles (Gazella thomsoni) killed by two species of predators were compared. The wild dog, a coursing predator, was predicted to take a greater proportion of young, old and sick animals than the cheetah, a stalker. As measured by the marrow fat content of limb bones, wild dogs captured more Thomson's gazelles in poor condition than cheetahs. This appeared to be a consequence of their preference for male gazelles, which were in worse condition than females. Cheetahs did not capture fewer young and old gazelles than wild dogs.