Bathygnathia magnifica sp.n., a new bathyal species of Gnathiidea (Crustacea, Isopoda), is described for science. It was collected from off southern Brazil, at 387 m depth. The present find seems of interest, not only because for the first time a species of Bathygnathia is reported at such a depth, but because it is the first species of the genus bearing eyes, in spite of depauperate.