Up to 90 % of the territory of the Slovak Paradise is covered by forests. There are mostly beech and mixed beech-fir forests, in gorges and peripheral areas the spruce forests. Very precious are the relict pine and larch stands in the most extreme rocky terrain. This variety is complemented by linden-maple scree forests and floodplain, mainly alder forests.

One of the rarest features of the national park is the vertical inversion in gorges. It causes the occurrence of warm-loving species of plants and animals at higher altitudes and cold-loving species at the bottom of gorges.

The rugged landscape relief and its composition create a space for a wide range of representatives within the plant kingdom. There are almost 1 000 species of higher plants, of which 35 are protected. There are plants preferring sunny rocky sites, meadow flowers, shade-loving plants in forests and cold-loving species growing at the bottom of gorges. From early spring until late autumn the nature of Slovak Paradise is adorned by precious and endangered species such as Pulsatilla slavica (Slovak Pasque Flower), Ligularia sibirica (Siberian Ligularia), Iris aphylla subsp. hungarica, Daphne cneorum L. (Garland Flower), Leontopodium alpinum (Edelweiss), the largest Slovak orchid Cypripedium calceolus (Lady’s-slipper Orchid) and many others.

In the Slovak Paradise there have been more than 4 000 species of invertebrates and 200 species of vertebrates identified so far, of which 130 species are protected and 65 endangered. Some precious beasts live here as well, such as Ursus arctos (Brown Bear), Lynx lynx (Eurasian Lynx), Canis Lupus (Gray Wolf) and Felis silvestris (Wild Cat). Even on the hiking trails you can meet Rupicapra rupicapra  rupicapra (Alpine Chamois), which was released into the Slovak Paradise in 1963. Rocky cliffs are home to birds of prey, endangered species of Aquila chrysaetos (Golden Eagle) and Aquila pomarina (Lesser Spotted Eagle) live here. Precious and also endangered bird is Tetrao urogallus (Capercaillie). Several species of bats found their home in the caves, among them also endangered species of Myotis mystacinus (Whiskered Bat) and Myotis nattereri (Natterer’s Bat). Precious Lutra lutra (European River Otter) and Lissotriton montandoni (Carpathian Newt), representing the group of amphibians, live beside water. There are almost 30 protected species among more than 2 000 species of butterflies, including the largest daily butterfly Parnassius apollo (Apollo).

To protect the precious and fragile nature of the Slovak Paradise the so-called ‘zones of silence’ were created, places which tourists can not enter, in order to safeguard the original natural environment and preserve the protected and endangered species.