Rhinoceros unicornis is threatened by continued loss of habitat and poaching. By the late 19th century, the Indian rhino was already thought to be a vanishing species. Extensive land clearing and modification of the rhino's habitat for cultivation and grazing was instrumental in reducing the rhino population to the point where hunting became critical, eliminating the Indian rhino from everywhere except the Chitwan Valley (Nepal), lowland Bhutan, the Teesta Valley (west Bengal, India) and the Brahmaputra Valley (Assam, India).
The great Indian rhino is found in tropical Asia, Nepal and northeastern India in flood- plain grassland, tall grass and reeds in jungle swamps, forests and near water. The western limit of its range moving eastward from the foothills of the Hindu Kush west of Peshawar, Pakistan in the early 1500's to the Nepal terai in the 20th century. The eastern limit of its historic range is uncertain. Some authors believe that it occurred in Cambodia, Laos, Thailand and Vietnam. Others believe that it never occurred east of the India-Myanmar border, and that reports from east of that border were mistaken, caused by confusing the Indian rhino with the Javan rhino or the Sumatran rhino.
The IUCN considers Rhinoceros unicornis as "Endangered". CITES lists the species as "Appendix 1".