The gaur and one species of eel have been discovered in this park. 10 new species previously unknown in Vietnam were discovered by scientists in the park. Phong Nha-Kẻ Bàng is home as well to a significant population of primates in Vietnam, with ten species and subspecies. These include the globally vulnerable pig-tailed macaque, Assam macaque, stump-tailed macaque and white-cheeked crested gibbon ("Nomascus leucogenys" and "Nomascus leucogenys siki"). The park is home to one of the largest populations of François' langur in Vietnam, including two different forms of the species. The area is known for its population of Hatinh and black langurs. 10 species of bats listed in the IUCN List of Threatened Species are recorded in this park. Of the 59 recorded reptile and amphibian species, 18 are listed in Vietnam's Red Data Book and 6 are listed in the IUCN Red List of Threatened Animals. The 72 fish species include 4 species endemic to the area, including "Danio quangbinhensis".