Fooden classified it is as one of two species under the genus Lagothrix with four sub-species (L. l. lagotricha, L. l. lugens, L. l. cana, and L. l.

[7][8][9] Many published sources use the specific name lagothricha rather than the etymologically correct lagotricha, since Fooden adopted this spelling when he revised the genus.

[10] The common woolly monkey is present in the upper Amazon basin in South America, ranging from the Rio Tapajos in Brazil, to eastern Peru, Ecuador and Colombia, with scattered populations north to Venezuela.

Females with dependents tend to eat more leaves, most likely because the leaves contain more protein, which helps the female produce more milk,[14] whereas juvenile woolly monkeys have been observed to eat more arthropods than other members of the group.

[13] The common woolly monkey exhibits generalist and opportunistic foraging behavior,[15] spending a large amount of time eating and moving in the pursuit of food, covering roughly 2 km per day.

[16] In certain seasons it is also common for groups to enter flooded forests, due to a higher concentration of berries.

Its large size makes the brown woolly monkey highly susceptible to being hunted by locals.

[25] Declining populations of woolly monkeys may have wider ecosystem impacts due to their function as seed dispersers and their role as both predator and prey.

Algodón Medio Putumayo and Bajo Putumayo-Yagua in Peru offer partial protection.

It has been suggested that the local extirpation of the species in some parts of its former range in Brazil was caused by the lack of hunting laws enforced upon indigenous groups.