This investigation of the diet of 801 corkwing wrasse (Crenilabrus melops: Teleostei; Labridae) from Galway Bay and a sample of 51 corkwings from Dinard has shown that this species is primarily a carnivorous feeder, taking a varied diet with molluscs and crustaceans predominating. A gradual, size-related dietary shift was apparent, crustacean food being favoured by the younger, smaller fish and molluscan food by older, larger fish. A decrease in niche breadth indicated an increase in dietary specialization with increasing length. Little seasonal variation was observed in the consumption of the major food categories. Feeding intensity, however, was influenced by the sea-water temperature. Non-feeding fish were recorded only between November and March in Galway Bay, and approximately two-thirds of the population examined in February had empty guts. Feeding intensity of males was significantly lower than that of females during the breeding season.