The distinctiveness of the European Galerina marginata and the American G. autumnalis is tested with analyses of DNA sequences from the internal transcribed spacer (ITS-2) of the nuclear ribosomal repeat and RFLP analysis of the entire ITS region. European and North American material from six taxa described in Galerina subgenus Naucoriopsis are included along with out-group material of six taxa representing two other subgenera of Galerina. The results do not indicate any genetic difference between species by Smith & Singer (1964) referred to the two ‘stirpes’ Marginata and Autumnalis of Naucoriopsis, i.e. G. autumnalis, G. marginata, G. oregonensis, G. pseudomycenopsis, G. unicolor, and G. venenata and all except G. pseudomycenopsis are considered later synonyms of G. marginata. Galerina badipes (syn. G. cedretorum var. bispora of ‘stirps’ Cedretorum is well supported as a distinct species. Subgenus Naucoriopsis appears as a distinct infrageneric unit well separated from the infrageneric units represented by the out-group species.