A species of the terrestrial isopod genus Porcellionides Miers, 1877 have a new record presented in this paper. Porcellionides pruinosus (Brandt, 1833), previously known in Brazil only from the states of Pará, Bahia, São Paulo, Santa Catarina, and Rio Grande do Sul, is recorded for the first time from Trindade Island, 1,140 km off Espírito Santo state coast. Porcellionides pruinosus is commonly recorded from urban habitats, being this record its first from an oceanic island.