The Guayanan Highlands moist forests (NT0124) is an ecoregion in the south of Venezuela, the north of Brazil, and also within Guyana, Suriname, and French Guiana.

The region has been inaccessible in the past and is generally fairly intact, apart from the north and northeast where large scale agriculture, ranching and mining operations are steadily encroaching on the ecosystem.

The Guayanan Highlands ecoregion is an "island" of higher land surrounded by lower grasslands and forests collectively known as the Guiana Shield.

[3] The peneplains hold evergreen forests with dense canopies of 30 to 40 metres (98 to 131 ft) with emergent trees in the Calophyllum, Anacardium, Manilkara, Protium, Inga, Parkia, Copaifera, Erythrina and Dipteryx genera.

Common trees on the plains include Micropholis melinoniana, Dacryodes species, Euterpe precatoria and Quassia cedron.

Floodplain trees include Caryocar microcarpum, Caraipa densifolia, Macrolobium acaciaefolium, Abuta grandfolia and Panopsis rubescens.

[2] 209 species of mammals have been recorded, including jaguar (Panthera onca), cougar (Puma concolor), South American tapir (Tapirus terrestris), white-lipped peccary (Tayassu pecari), collared peccary (Pecari tajacu), brocket deer (Mazama genus), white-eared opossum (Didelphis albiventris), big lutrine opossum (Lutreolina crassicaudata), Robinson's mouse opossum (Marmosa robinsoni), Davy's naked-backed bat (Pteronotus davyi), Fernandez's sword-nosed bat (Lonchorhina fernandezi), highland yellow-shouldered bat (Sturnira ludovici), eastern lowland olingo (Bassaricyon alleni), fiery squirrel (Sciurus flammifer), Guyanan spiny rat (Proechimys hoplomyoides) and Orinoco agouti (Dasyprocta guamara).

[2] Endangered mammals include black bearded saki (Chiropotes satanas), Fernandez's sword-nosed bat (Lonchorhina fernandezi) and giant otter (Pteronura brasiliensis).

[7] 631 species of birds have been recorded, including white-cheeked pintail (Anas bahamensis), aplomado falcon (Falco femoralis), brown-throated parakeet (Eupsittula pertinax), pavonine cuckoo (Dromococcyx pavoninus), Middle American screech owl (Megascops guatemalae), burrowing owl (Athene cunicularia), emeralds and hummingbirds in the Amazilia genus, chestnut-tipped toucanet (Aulacorhynchus derbianus), smoke-colored pewee (Contopus fumigatus), orange-crowned oriole (Icterus auricapillus), grey seedeater (Sporophila intermedia), two-banded warbler (Myiothlypis bivittata) and black-backed water tyrant (Fluvicola albiventer).

Near urban centers in the north and northeast of the ecoregion the habitat is steadily being destroyed by large-scale agriculture, cattle ranching and mining.

Planned hydroelectric dams on the Caroni and Paragua rivers would flood huge areas with devastating effect on the riparian habitats.