Buceros bicornis has a wide distribution, occurring in China (rare resident in west and south-west Yunnan and south-east Tibet), India (locally fairly common, but declining), Nepal (local and uncommon, largely in protected areas), Bhutan (fairly common), Bangladesh (vagrant), Myanmar (scarce to locally common resident throughout), Thailand (widespread, generally scarce but locally common), Laos (formerly common; currently widespread but scarce and a major decline has clearly occurred), Vietnam (rare and declining resident), Cambodia (rare), Peninsular Malaysia (uncommon to more or less common) and Indonesia (uncommon on Sumatra).