Among the 60 present species of mammals that inhabit the area of the National Park, 9 belongs to insectivores (Insectivora), 16 to bats (Chiroptera), 13 to carnivores (Carnivora), 3 to a row of ungulates (Arctiodactyla) 17 to rodents (Rodentia) and 1 to a row of lagomorphs (Lagomorpha).
Assumption is that along with the surely present species in the wider area 9 more species of bats resides here.

Within the group of rodents (Rodentia) there are 4 species that also live in this area, such as: alpine vole (Microtus multiplex), the garden dormouse (Eliomys quercinus), nutria (Myocastor coypus) and the dwarf mouse (Micromys minutus). Among the mammals of the National Park there are two endemic species: runat vole (Chionomys nivalis) – Euro – Mediterranean endemic and alpine vole (Microtus multiplex) – eastern Alps endemic.

According to the Law on Nature Protection and the Regulation on the protection of certain species of mammals, Mammalia (N.N. 31/95), 33 species of mammals at the area of Una and the National Park are protected, while 8 species are protected by the Ordinance of the closed season. Out of protected mammals along with many endangered and sensitive species of bats, three big beasts, the three largest European predators – a wolf, lynx and a bear, should be pointed out as well. There is a large number of – otters, badgers, weasels and ermine, out of a group of beasts. There are 17 species in two categories, at the IUCN list of endangered mammals in Europe, that are endangered. According to the lists of Bern Convention, which protects European wildlife and natural habitats, 50 species from the area of the National Park are protected. Twenty-four species are on Appendix II (strictly protected species), while 26 species are in Appendix III (of protected fauna).