Five opisthobranch species (Pleurobranchus testudinarius, Caloria elegans, Dondice banyulensis, Janolus cristatus and Flabellina babai) unrecorded up-to-date in the Greek seas along with Scyllaea pelagica and Notarchus punctatus species reported after more than a century from their first finding in the Mediterranean (southern Aegean—Milos and Serifos Islands) by Forbes (1844), and zoogeographical and ecological details, are presented in this study. Scyllaea pelagica, N. punctatus and F. babai seem to have a narrow distribution in Greek waters while the rest of the species seem well established similar to what has been reported from other seas in the western Mediterranean or the Atlantic.
