Although the diversity of marine molluscs along the Humboldt Current ecosystem is relatively well known, some groups such as opisthobranch sea slugs and snails (Gastropoda, Heterobranchia) have received little attention. Herein, we critically review and update the taxonomical composition of Acteonoidea, Nudi pleura, Euopisthobranchia and marine panpulmonates Sacoglossa and Acochlida from coastal Peruvian waters. Our checklist comprises a total of 56 species belonging to 30 families. The nudibranch species Tritonia sp., Tyrinna nobilis and Diaulula variolata are reported for the first time in the Peruvian coast. We also add new collection localities for 19 species, including Bulla punctulata, Navanax aenigmaticus, Haminoea peruviana, Aplysia juliana, Dolabrifera dolabrifera, Elysia diomedea, Elysia hedgpethi, Doris fontainei, Baptodoris peruviana, Polycera alabe, Felimare agassizii, Doto uva, Dendronotus cf. venustus, Flabellina cynara, Fiona pinnata, Spurilla cf. neapolitana, Phidiana lottini, Bajaeolis bertschi and Glaucus atlanticus. The species Bulla punctulata, H. peruviana, F. cynara and A. juliana, which are usually distributed in the Tropical East Pacific, are now reported also from the Warm Temperate Southeastern Pacific Province. Earlier records of thecosome pteropods and several more or less adequately described Aplysia species still need taxonomic revision. Several benthic Peruvian opisthobranch species assumed to show wide or even circumtropical distributions are likely to be part of species complexes. Integrative approaches including molecular species characterization and intensified field work are necessary to enhance the knowledge on the diversity of opisthobranchs from Peru.