Poaching is a severe threat to Rhinoceros sondaicus especially as the population is so small. Its horn is valued highly for use in oriental medicine. Habitat loss due to clearing of lowland forest as a consequence of commercial logging and for agriculture causing shifts in the composition of vegetation (especially in the Udjung Kulon National Park) is a serious threat to the Javan rhino.
Javan rhinos are extremely vulnerable to any extraordinary event such as the viral infection that killed five of these animals in the 1980's.
The Javan rhino's habitat is lowland tropical rainforest. Historically it was found throughout: Malaya, Burma, Thailand, Indochina, Java, Sumatra and Northern India. The Javan rhino is possibly the rarest of the rhino species with fewer than 100 animals surviving in only two known locations: one in Indonesia and the other in Vietnam.
The IUCN 1997 estimate of javan rhino was 70. In Ujung Kulon National Park on the island of Java in Indonesia there were estimated 40 - 60 rhino surviving and in Cat Loc Nature Reserve in Vietnam there were 10-15 rhino surviving. By 2017, it was estimated only 67 Javan rhinos left in the world.
The IUCN considers Rhinoceros sondaicus as "Critically Endangered". CITES lists the species as "Appendix 1".