An annotated list is presented of a total of 87 taxa of macrophytes (two bryophytes, one pteridophyte, 84 spermatophytes) found in and around 11 aquatic ecosystems of Peloponnisos (Greece), 10 of which have been investigated for the first time. Riccia fluitans, Utricularia australis, Potamogeton gramineus and P. pusillus are rare species in Greece. Ranuncalus peltatus subsp. baudotii and R. peltatus subsp. fucoides are given as new to the Greek mainland. Ranunculus rionii, Utricularia australis, Potanogeton berchtoldii, P. nodosus and P. trichoides are recorded for the first time from Peloponnisos
