Fourteen rare or poorly known sponge species have been found in the Aegean Sea. The species Pachastrissa pathologica, Calthropella stelligera, Weberella verrucosa, Aaptos papillatus, Timea geministellata, Spiroxya heteroclita, Clathria translata, Hymedesmia simillima, Mycale serrulata, Myrmekioderma spelaea, Callyspongia septimaniensis and Ircinia pipetta are new records for the eastern Mediterranean while the species Geodia barretti and Petrosia vansoesti are reported for the first time from the Mediterranean Sea. Information on their morphology, geographical and bathymetrical distribution is given and discussed.