Aristophanes and Eupolis, together with Kratinos,were the most significant poets of Attic old comedy in the 5th century BC. Their names are usually linked because in antiquity they were seen as bitter rivals who attacked each other on the stage. Natalia Kyriakidi examines the expression of mutual rivalry between the two comic poets and showsthat the competition which can be sensed in thecomedies can be explained in the context of the atmosphere of mockery in the genre.