L'Hoest's monkey is a largely terrestrial primate that inhabits lowland and montane forests in eastern Central Africa. It typically lives in groups composed of a single adult male and multiple females and juveniles (a harem-based social structure), and matrilineal bonds are strong within the group; allomaternal care, in which juveniles are cared for by multiple females, is observed. Its diet is primarily fruit, and it also consumes leaves, small mammals, and insects. Populations have declined due to habitat destruction and hunting, and the species is classified as Vulnerable (IUCN Red List Category II).