Microcharon arganoi, a new Microparasellid from subterranean waters of Southern Italy is described. For the shape and ornamentation of pleopod II of females and for the morphology of pleopod II of males, the new species is clearly related to the phyletic line which includes all the Western and French species of the genus. However, from all these species and from all the other ones M. arganoi differs by the ornamentation of the antennae, maxillipeds and pereiopeds, by the shape and ornamentation of pleopods I and II of males and II of females. and by ratio endopod/exopod of pleopod III. The new species is the first one from the subterranean freshwaters of Italy.