This paper deals with a new species of a paramphistomid trematode, Taxorchis caviae n. sp., found in a wild Brazilian rodent, Cavia aperea aperea Erxleben, 1777. Differences between T. caviae and species of Cladorchis Fischoeder, 1901, Stichorchis Fischoeder, 1901 and Taxorchis Fischoeder, 1901, are discussed and some alteration in the diagnosis of the genus Taxorchis are proposed.