In the late 19th and early 20th centuries Prince Albert I of Monaco promoted 13 cruises that sampled the Azorean waters. During those cruises a total of 2624 nominal marine species were reported in the area. This work assembles the biological data provided by these expeditions to the Azores in a geo-referenced database. Faunal lists for seven invertebrate groups (Echiura, Sipuncula, Cephalopoda, Annelida, Brachiopoda, Chaetognatha and Echinodermata) are compiled. The checklist includes 331 nominal species, of which 310 are valid names: 1 echiurid; 11 sipunculids; 32 cephalopods; 130 annelids; 4 brachiopods; 14 chaetognaths; and 118 echinoderms. Eighteen percent are synonyms, 29% of the species were allocated to a different genus, 2.8% were misspellings and corrections due to gender or concordance rules, 0.8% were specific epithets allocated to sub-specific level or vice-versa, the rest were validated directly (without any modification in their nomenclature)
