Kulen-Promtep Wildlife Sanctuary is the largest protected area in Cambodia. The sanctuary was originally designated to protect the kouprey Bos sauveli (Grey Ox, Kouprey), currently listed by the IUCN Red List of Threatened Species as Critically Endangered. Kulen-Promtep Wildlife Sanctuary contains a variety of habitats including lowland evergreen and deciduous dipterocarp forest as well as the second largest swamp in the country. The sanctuary is home to important bird species such as sarus crane, green peafowl, giant Ibis, grey-headed fish Eagle

Despite being designated a wildlife sanctuary in 1993, relatively few published mammalian records exist for this area. Those available suggest the sanctuary houses significant species such as the fishing cat, Indochinese lutung, northern pig-tailed macaque, long-tailed macaque, pileated gibbon and Bengal slow loris, Black giant squirrel, Asiatic golden cat, Sun bear, Gaur etc.