It was Philip Lutley Sclater who originally gave the specific name Cercopithecus lhoesti in honor of François L'Hoëst [nl], director of the Antwerp Zoo, in 1898.

[1] Molecular studies published by Anthony Tosi in 2003 had raised doubts about the classification of L'Hoest's monkey as a member of the genus Cercopithecus.

[10] L'Hoest's monkey occurs in northeastern Democratic Republic of the Congo, Rwanda, Burundi, and western Uganda.

[13] C. lhoesti lives in fairly small groups dominated by females and have only a single male.

[6] L'Hoest's monkey breeds seasonally, with the timing depending on the area.

Birth usually occurs at the end of the dry season, which allows lactation when rainfall is highest.

[10] She will eat the placenta and lick the baby clean while it hangs on to her belly.

[15] In the wild, L'Hoest's monkey is primarily a herbivore, which will mostly eat fruit, mushrooms, herbs,[16] roots, and leaves.