The checklist of Tanaidacea of Greece was developed in the framework of the LifeWatchGreece Research Infrastructure (ESFRI) project and coordinated by the Hellenic Centre for Marine Research during the period 2013-2015. By applying the Greek Taxon Information System (GTIS) of this project, a complete checklist of species recorded from Greek Seas has been developed. The objectives of the present study were to update and cross-check all tanaidacean species known to occur in Greek Seas. Inaccuracies and omissions according to recent literature and the current taxonomic status were also investigated. The up-to-date checklist of Tanaidacea of Greece comprises 20 species, classified to 11 genera and five families.