Bone fragments of large anadromous salmon in the Middle Palaeolithic archaeological layers of Kudaro 3 cave (Caucasus) suggested fish consumption by archaic Hominins, such as Neandertals. However, large carnivores such as Asiatic cave bears (Ursus kudarensis) and cave lions (Panthera spelaea) were also found in the cave and could have been responsible for such an accumulation. The diet of these carnivores was evaluated using carbon, nitrogen and sulphur isotopes in faunal bone collagen. The results suggest that anadromous fish were neither part of the diet of either cave bear (vegetarian) or cave lion (predators of herbivores from arid areas) and therefore provide indirect support to the idea that Middle Palaeolithic Hominins, probably Neandertals, were able to consume fish when it was available.