The occurrence of the alien species Anadara kagoshimensis is reported for the first time in the Ría de Arousa (Galicia, NW Spain) during 2013. Living specimens of this species have been recognized by morphological analysis. The cytochrome c oxidase subunit I gene has been partially sequenced and Maximum likelihood and Bayesian analyses carried out to confirm its identification. This new record reaffirms the presence of A. kagoshimensis, previously reported as Anadara inaequivalvis, along the Atlantic European coast extending the known distribution range in Spanish waters to the south.