The genus Chroaptomus Sharp, 1885 (Staphylininae: Staphylinini), distributed from central Mexico to northwestern Argentina, is revised using characters of external morphology, including sexual dimorphism, and male and female genitalia. Chroaptomus comprises five species, of which two are described as new: C. centralis Chani-Posse and C. mexicanus Chani-Posse and Navarrete-Heredia. Other valid species of the genus are: C. flagrans (Erichson), C. regalis Sharp and C. coelites (Erichson) stat. rev. Lectotypes are designated for C. flagrans (Erichson) and C. regalis Sharp. Belonuchus richteri (Bernhauer), comb. n. is excluded from Chroaptomus. Belonuchus castaneus, new name, is proposed for Belonuchus richteri Bernhauer, 1922, which is a junior secondary homonym of Belonuchus richteri (Bernhauer, 1912). This article includes a redescription of the genus, redescriptions or descriptions of its five species, an identification key, photographs illustrating sexual dimorphic characters, drawings of genital features, a cladogram and a distribution map. The cladistic analysis shows that Chroaptomus comprises a natural group of five species, characterized by nine synapomorphies from the external morphology and male genitalia.