The importance of predation by the whiting (Merlangius merlangus ) from the Celtic Sea has been studied by analysis of stomach contents. Eight hundred and thirteen whitings have been examined during 1984-1986 period. Fish food totalizes 97% of food. It is chiefly a swimming species: no cannibalism has been observed. The daily food index varies between 2 and 4% according to the length and the annual consumption on fishes of nominal catches (11230 t for 1983) would reach 135,000 t corresponding to species already fished for human consumption and the fish meal industry.