Blackchin guitarfish, Rhinobatos cemiculus, is rather abundantly captured in the eastern tropical Atlantic, especially off Senegal and Mauritania. In the Mediterranean western basin, R. cemiculus is unknown at present off the European shore but is rather frequent off southern areas; conversely, the species occurs throughout the eastern basin. Two large specimens recorded for the first time in İzmir Bay, northern Aegean Sea, are reported and described in this note. These findings constitute the northernmost records of R. cemiculus in both the Aegean Sea and the Mediterranean Sea, and they significantly extend the species' distribution known to date. [ABSTRACT FROM AUTHOR]