We here report on the systematics, paleoecology and biostratigraphy of a rare, but diversified gastropod fauna found in the early Pliocene sediments of the Agia Triada section in the Falanthi Basin (Peloponnese, Greece). Sixty-one species belonging to forty-eight genera are identified, allowing biostratigraphic assignment to the Mediterranean Plio-Pleistocene Molluscan Unit 1 (MPPMU1). Planktonic foraminiferal biostratigraphic analyses indicate that the Agia Triada section correlates with Zones MPL2 and MPL3, corresponding to the latest Zanclean. A comparison is further carried out between the studied assemblages and those previously documented from the Atlantic coasts of Europe and the Mediterranean region. New information on the palaeobiogeography of early Pliocene gastropod fauna is given, as seven species from the Mediterranean, thirty-nine species from the eastern Mediterranean and forty-four species from Greece, are documented here for the first time.