The occurrence of the opisthobranchs Diaphana globosa, Hermaeopsis variopicta, Doris bertheloti, Rostanga rubra, Janolus cristatus and Flabellina bulbosa in the Azores is reported for the first time. Our findings expand the known geographical distribution of these species in the north-east Atlantic Ocean and increase the known diversity of opisthobranchs in the archipelago to 150 species. These results provide further support for the well-documented affinity of the Azorean marine biota to the eastern Atlantic and Mediterranean coasts.