Around 1000 animal species inhabit in the national park, predominantly invertebrates. The special conditions of isolation of the archipelago favoured the appearance of many endemic species and this exclusivity is especially manifested in the world of the invertebrates. Regarding the vertebrate fauna, birds linked to the laurel have a great importance and, among them, the paloma rabiche and turqué are, without doubt, the most emblematic.

Many species of invertebrates adapted themselves to the use of very determined microhabitats, or even to depend on some species of plant in particular. In the leaves, we can find the endemic chicharras of the genus Canariola, the omnivorous grasshopper Calliphona or the gorgojos of the genus Laparocerus. The bark and the dead wood provide food and shelter to a large number of small creatures, like the cockroach Phyllodromica or the endemic tijeretas of the genus Guanchia. Some animals carry their specialization until the end, such as the tiny gorgojo Rhopalomesites euphorbiae, which only feeds on the also threatened tabaiba de monte (Euphorbia mellifera).

Other invertebrates prefer to move through the forest floor. It is the case of the opiliones and of various species of molluscs, such as the colourful Napaeus and the false slugs of the genus Plutonia, among which it is particularly striking by its size the Plutonia oromii, which can exceed 5 cm in length. These molluscs have an important role in the decomposition of the vegetable matter. On the forest floor, it is worth highlighting the presence of beetle hunters, such as the smelly beetle Broscus crassimargo. It is black, has strong jaws and, when it feels bothered or threatened, emits a strong scent of rotten cheese.

The vertebrate fauna of an island is poorer in species that the one that inhabits the mainland. The fact of being surrounded by water limits the arrival of many species, especially mammals. Therefore, since they can easily reach the island, birds stand out within the vertebrates, with the presence of 28 species.

Concerning the birds of prey, there are three diurnal species in the park: the gavilán (Accipiter nisus ssp.granti), whose adjustment to the forests (short wings, long tail) makes it the predator par excellence of the canary jungles, being very difficult to observe it; the aguililla (Buteo buteo ssp.insularum) highlights by its size and shape of fly and glide on open spaces and, moreover, it is the largest breeding bird of the national park; and the cernícalo (Falco tinnunculus ssp.canariensis), effective hunter of small reptiles and insects, which prefers open spaces. On the other hand, the búho chico (Asio otus ssp.canariensis) is the only night prey in the park, since the rare lechuza (Tyto alba ssp.alba) does not enter in the mountain. Both species are fundamental in the control of rats and mice.

Without a doubt, the "stars" of the forest birds are the two endemic pigeons to the Canary Islands: the paloma turqué (Columba bollii) and the paloma rabique (Columba junoniae). Probably, they had much to do with the arrival of the laurel to the Canary Islands, bringing the seeds of the mainland to the islands when the laurel forest still covered the Mediterranean basin before the glaciations. These are two species that are perfectly adapted to the mountain. The turqué nests in trees and the rabiche in platforms and cliffs (both only lay one egg, when the majority of the pigeon species lay two).

With them, birds of smaller size share the ecosystem, most of them insectivorous or omnivorous: the pinzón vulgar (Fringilla coelebs ssp.tintillon), the herrerillo (Cyanistes caeruleus ssp.teneriffae) , the hornero (Phylloscopus canariensis), the reyezuelo or bandera (Regulus teneriffae) and the calandra or petirrojo ( Erithacus rubecula ssp.mycrorhynchus). All of them are fairly easy to see, even if they do not have the wealth and importance of the mirlo (Turdus merula ssp.cabrerae), a first-order "environmentalist". It is one of the main responsible for dispersing the seeds of laurel through the island. The cuervo (Corvus corax ssp.tingitanus), the vencejo (Apus unicolor), the canario (Serinus canaria) and the currucas (Sylvia sps.) are also present in the Garajonay, although they are not forest birds.

Reptiles and amphibians do not abound in Garajonay since it is a cloudy and cooler ecosystem. However, in the sunniest areas of the park, sometimes it is possible to find the three endemic species of reptiles of the island: the lagarto (Gallotia caesaris ssp.gomerae), the lisa (Chalcides viridanus ssp.coeruleopunctatus) and the pracan (Tarentola gomerensis), the latter active during the night. The only amphibian that exists in the park is the rana (Hyla meridionalis).

The indigenous mammals (who came by their own means) are only represented by the bats. The four species present on the island were also found in the park: the murciélago rabudo (Tadarida teniotis), the murciélago de Madeira(Pipistrellus maderensis), the murciélago montañero (Hypsugo savii) and the murciélago de bosque (Barbastella barbastellus ssp.guanchae). Cracks, cavities in trees and abandoned buildings are the preferred habitats of the gomero bats.

Other mammals that inhabit Garajonay were introduced by the human being. The rat (Ratus ratus), the mouse (Mus musculus) , the rabbit (Oryctolagus cunniculus) and the gato cimarrón (Felix catus) have been reproducing themselves on the island for hundreds of years. Their negative impact on the fauna, especially in the case of reptiles and birds, represents a serious conservation issue. Probably, the fact that the giant lizard of La Gomera (Gallotia bravoana) is the most threatened reptile of the planet has a lot to do with the populations of rodents and wild cats on the island. The control of their populations is very complicated and its eradication is impossible.

Some of the typical species of the park are endangered, as it is reflected in the following chart. These species are protected by its inclusion in any of the categories of threat ( "in danger of extinction" (END) or "vulnerable" (VUL)) and are listed both in the Spanish Catalogue of Endangered Species and in the Canary Island Catalogue of Protected Species: