The New World species of the staphylinid subfamily Micropeplinae are revised. Three genera are recognized: Kalissus Leconte with 1 species, Micropeplus Latreille with 11 species, and Peplomicrus Bernhauer with 3 species. Of the three previously recognized subgenera of Micropeplus , Arrhenopeplus Koch is placed in synonymy with Micropeplus , and Peplomicrus is elevated to generic status. New species are: M . durangoensis from Mexico, M . neotomae from California and Oregon, M . browni from eastern Canada and the United States, M . robustus from California and Oregon, M . lecontei from southern California, and P . dybasi from Costa Rica and Panama. Micropeplus obliquus Leconte is placed in synonymy with M . sculptus Leconte, and M . oregonensis Hatch is placed in synonymy with M . punctatus Leconte. The genus Micropeplus is divided into six species groups based on an examination of both Old and New World species. A checklist of the species of Micropeplinae places all the described species in the proposed classification. Two African species, M . africanus Cameron and M . carayoni Jarrige, and one Central American species, M . acumen Sharp, are transferred to the genus Peplomicrus .