Due to its large size, the gorilla has only two major predators. Humans are by far the main predator of G. gorilla, killing animals for their meat, and body parts and in retaliation for damage to crops. Leopards are important predators at some sites, with G. gorilla accounting for 4–9% of biomass consumed. Gorilla gorilla, like G.beringei, is prone to many pests and diseases.

The majority of western lowland gorillas are in Gabon and Congo. Their number in Gabon was estimated at between 28,000 and 42,000 in the early 1980s. Congo had a similar number in 1989–1990. Cameroon held ca. 15,000 gorillas in 1998. Equatorial Guinea (Rio Muni/Mbini) supported >3000 G. g. gorilla in 2011. In 2009, the total number of western gorillas was estimated at >150,000.