The fauna of El Ávila is highly diverse. In its forests there are more than 120 mammal species, approximately 20 amphibian species and 30 reptile species. The main attraction, however, is the park's 500 bird species, representing approximately 36% of all Venezuela's avifauna. Among the birds are nine endemic species to Venezuela: the violet-chested hummingbird (Sternoclyta cyanopectus), black-throated spinetail (Synallaxis castanea), guttulated foliage-gleaner (Syndactyla guttulata), scallop-breasted antpitta (Grallaricula loricata), Caracas tapaculo (Scytalopus caracae), handsome fruiteater (Pipreola formosa), white-bearded flycatcher (Phelpsia inornata), Venezuelan bristle-tyrant (Pogonotriccus venezuelanus) and rufous-cheeked tanager (Tangara rufigenis) (Sharpe 2001).
Some locally and globally endangered bird species live in El Ávila as well, including the helmeted curassow (Pauxi pauxi), fasciated tiger-heron (Tigrisoma fasciatum) and black-and-white hawk-eagle (Spizastur melanoleucus) (Rodríguez & Rojas-Suárez 1999, Birdlife International 2000).
El Ávila is home to notable mammals like the red howler monkey (Alouatta seniculus), three-toed sloth (Bradypus variegatus), armadillo (Dasypus novencinctus), porcupine (Coendou prehensilis), the small anteater (Tamandua tetradactyla), fox (Cerdocyon thous), squirrel (Sciurus granatensis), weasel (Mustela frenata), paca (Agouti paca) and the tapir (Tapirus terrestris) (Naveda 1988, Manara 1998).
More than one hundred butterfly species have been reported for El Ávila, among them are Metamorpha epaphus, Dione moneta, Morpho peleides, Daethria mesticus, Chlosyne lacinia and Oleria stella (Manara 1998).
More than 1,800 plant species are registered in El Ávila, although some botanists believe there could be as many as 2,000 species. Several documented species are endemic to the Cordillera de la Costa Mountains, like the shrubs resinoso (Verbesina laevifolia), cafecillo (Palicourea pittieri), clavo morado (Monochaetum humboldtianum), romerillo (Arcytophilum nitidum) and the giant tree known as "el nińo" (Gyranthera caribensis). Other notable plants present in the highest zones of El Ávila , and endemic to the Andes, are the frailejón arbolito (Libanothamnus neriifolius), the falso frailejón (Liabum megacephalum), the quina (Cinchona pubescens) and 13 other species. In the sub-páramo zone the most abundant plant species are the shrub incienso (Libanothamus neriifolius) and the grasses carrizo (Arthrostylidium subpectuinatum) and bambucillo (Chusquea spp.), the latter is limited to elevations above 1400 m. Finally, at least 17 species are endemic to El Ávila itself, including the shrub viravira avileńa (Archyrocline flavida), three Sapindaceae from the genus Paullinia and the herbaceous Warreella cyanea (Steyemark & Huber 1978, Manara 1998).
The park hosts more than 180 orchid species, including Cychnoches chlorochilon, Stanhopea wardii, Schomburgia undulata, Epidendrum fimbriatum, Lycaste macrophylla, Oncidium papilio, Brassavola cucullata, Acineta superba and Venezuela's national flower, Cattleya mossiae. Some species such as Oncidium zebrinum and O. falcipetalum, found in the Andes of Venezuela, Colombia and Perú, flower in the highest zones of El Ávila sub-páramo (Steyemark & Huber 1978, Manara 1998).
The forests contain several species of lichens and fungi notable for their beauty or rarity, such as the beautiful pulpo rojo (Phallades sp.), the edible colmenilla (Morcella sp.), cacho de venado (Clavaria sp.) and an El Ávila endemic, estrella de tierra (Myriostoma coliforme). A pteridofite, Lycopodium caracasum, is also endemic to the park (Steyemark & Huber 1978, Manara 1998).
At the southern slope of the park there are several forests patches containing the palm Ceroxylon ceriferum from which leaves are cut and used by catholics during Easter ceremonies.