The ant genus Prionopelta Mayr, 1866 is revised for the Neotropics. Morphological traits combined with geographical data led to the recognition of eight species, four of them described here as new: Prionopelta dubia sp. n., Prionopelta menininha sp. n., Prionopelta minuta sp. n., and Prionopelta tapatia sp. n. Prionopelta marthae Forel, 1909 is proposed as a new junior synonym of Prionopelta antillana Forel, 1909. External morphological descriptions of the worker caste for all species are provided, as well as for some of the males and queens, mostly described here for the first time. Identification keys for all known castes, distribution maps and high-resolution illustrations are supplied for all species.