Four new species of shallow-water marine gastropods belonging to the family Rissoidae are described from the Archipelago of the Azores: Setiaalexandrae sp. n., Setiaermelindoi sp. n., Setianetoae sp. n., and Manzoniamartinsi sp. n. These novelties increase the regional rissoid fauna to 39 species, of which 29 live in shallow-water habitats. A list of the species of Rissoidae from the Azores is presented based on data from the literature and new material examined.
Keywords: Caenogastropoda; Eastern Atlantic; Manzonia; Rissooidea; Setia; Taxonomy.