The Ypsolophid genus Rhabdocosma Meyrick is reviewed. It comprises two known species: R. aglaophanes Meyrick and R. dolini Gershenson, and one new species from Japan, R. nematopogonites Sohn, sp. nov. Photos of imagoes and male genitalia are provided for all three species of Rhadocosma. A close relationship between R. dolini and the new species, and its significance in the biogeography and world species diversity of Rhabdocosma, are discussed.