During April till November 1979 the food consumption of the adult shore crab, Carcinus maenas, in de Dutch Wadden Sea has been investigated. Daily ration (DR) was determined at 22.04 mg ash-free dry weight per g ash-free dry weight crab. During 24 hours two periods of maximum food intake were observed: the first period starts at the beginning of the night, the second about 12 hours later, probably depending on the digestion rate. The food of the shore crabs, examined in July and September, merely existed of macrozoöbenthos (e.g. Crangon crangon, molluscs and polychaetes). The total consumption of the shore crabs on the Balgzand area amounted in 1978 to 1.39 g ash-free dry weight m-2.y-2 and in 1979 to 0.66 g ash-free dry weight m-2.y-1.