ABSTRACT We report new records of Gnamptogenys caelata Kempf (1967) and Gnamptogenys minuta (Emery, 1896) from Brazil. We also describe Gnamptogenys piei n. sp. from Southeast Brazil. This distinctive new species is known only from a single worker found in leaf litter from montane forests of the Mantiqueira mountains in Itatiaia National Park, Rio de Janeiro State, Brazil. The specimen was collected at 1991 m above sea level, an infrequent altitude for minuta-group ants, usually more common at lower altitudes. The new species is imaged, compared with other minuta-group species, and an updated identification key for all known species of the minuta-group is included.