A new species of oribatid mite of the genus Pseudotocepheus (Oribatida, Otocepheidae) is described from Sphagnum-mosses on swamps in the vicinity of Punta Arenas of Chile. Pseudotocepheus puntaarenasensis sp. nov. is morphologically most similar to P. sexdentatus (Trägårdh, 1931), however, it differs from the latter by the smaller body size, parallel costulae basally, interlamellar setae distanced from costulae and similar length of rostral and lamellar setae. The taxonomic status of the genus Constrictocepheus Grobler, 1998 is discussed; it is considered as a junior synonym of Pseudotocepheus. The initial systematic placement of eight species of Pseudotocepheus, which has been combined with Constrictocepheus, is supported. An identification key to all known species of Pseudotocepheus from the Neotropical region is given.