The diets of scaldfish Arnoglossus laterna, dab Limanda limanda, lemon sole Microstomus kitt, long rough dab Hippoglossoides platessoides, solenette Buglossidium luteum, thickback sole Microchirus variegatus, plaice Pleuronectes platessa, witch Glyptocephalus cynoglossus and Dover sole Solea solea in the Irish Sea were determined for March and October 1997 and 1998 and compared. Similarities in diets were examined using multivariate analyses. In general, there were differences in diet between species and generally the diets were similar within a species. Smaller individuals tended to have a similar diet. There were seasonal changes in the diets of individual species. Likewise, the overlap in diets between species changed between seasons and to a certain extent between sediment types.