The Tricholoma biodiversity of the Aegean region of Turkey has been determined and reported in this study. As a consequence of field and laboratory studies, 31 Tricholoma species have been identified, and five of them (T. filamentosum, T. frondosae, T. quercetorum, T. rufenum, and T. sudum) have been reported for the first time from Turkey. The identification key of the determined taxa is given with this study.