A variety of habitats influenced the richness and diversity of the fauna of the Nature Park.
The barbell (Barbus peloponnesius), brown trout (Salmo trutta), bleak (Alburnus alburnus), chub (Leuciscus cephalus), bullhead (Cottus gobio), and one species of lamprey (Petromyzontidae) live in cold, salmon type waters.
The amphibians are represented with fire salamander (Salamandra salamandra), yellow-bellied toad (Bombina variegata), common toad (Bufo bufo), green toad (Bufo viridis), Balkan stream frog (Rana graeca), and edible frog (Rana esculenta), and the reptiles with slow worm (Anguis fragilis), green lizard (Lacerta viridis), wall lizard (Podarcis muralis), smooth snake (Coronella austriaca), Aesculapian snake (Elaphe longissima), dice snake (Natrix tessellatа) and long-nosed Viper (Vipera ammodytes). All these species are included in the Preliminary Red List of Vertebrates of Serbia, and according to the current regulations, with the exception of three species of anurans, all other species are legally protected as natural rarities of Serbia.
The presence of 90 species of birds is determined so far, but it is certain that this number is not final. The presence of vulnerable and threatened species associated to specific habitats, such as short-toed eagle (Circaetus gallicus), capercaillie (Tetrao urogallus), corncrake (Crex crex), and willow tit (Parus montanus), is of particular significance. The national and international significance of the Nature Park for the conservation of birds is especially important considering that this region is inhabited by 31 species (27 nesting species), the protection of which is significant at the European level, and 29 species that are protected as natural rarities of Serbia.
The mammal fauna consists of 32 species, with the exclusion of bats, which are still not sufficiently studied. The mammals of the wider area of Mokra Gora include the European hedgehog (Erinaceus europaeus), red squirrel (Sciurus vulgaris), lesser mole rat (Nannospalax leucodon), bank vole (Clethrionomys glareolus), hazel dormouse (Muscardinus avellanarius), pine marten (Martes martes), beech marten (Martes foina), badger (Meles meles), wild cat (Felis silvestris), otter (Lutra lutra), red fox (Vulpes vulpes), grey wolf (Canis lupus), brown bear (Ursus arctos), roe deer (Capreolus capreolus), chamois (Rupicapra rupicapra), and many other species. As much as 22 species of mammals from this region are included in the Preliminary Red List of Vertebrates of Serbia, and, according to the criteria of the International Union for Conservation of Nature (IUCN), the category of vulnerable species (VU) includes the grey wolf, chamois, otter, and brown bear. According to the Convention on the Conservation of European Wildlife and Natural Habitats (the Bern Convention), 18 species of mammals are included in the third category of protection. These are species that are hunted or exploited in some other way, and therefore in need of some form of protection. The second category of protection includes the grey wolf, brown bear, and otter, which should be strictly protected by the Bern Convention.