We obtained new data on the existence of giant deer (Megaloceros giganteus Blum.) in Siberia during the Holocene. Bones and antler of giant deer from new localities in western (Baraba forest steppe) and eastern (Angara River basin) Siberia are dated by radiocarbon, ranging 7900-10,300 BP (ca 8800-12,200 cal BP). Based on these data, we can extend the 'Siberian' Early Holocene habitat of giant deer at least 2400 km to the east compared to previous works. The final extinction of giant deer turned out to be more complex than it was previously thought, with perhaps relatively large refugium in Western Siberia at 7900-7000 BP (ca 8800-7900 cal BP) which was reduced to the Trans-Urals region at 7000-6800 BP (ca 7900-7600 cal BP).