Oxygen uptake across plaice skin was unaffected by temporary arrest of skin blood flow. This indicates that oxygen taken up across the skin is consumed by the skin itself. Weight specific rate of O2-consumption of skin is estimated to be 1.7-1.9 times that of the entire fish. Total resting O2-consumption increased from 0.43 to 0.58 mg X kg-1 X min-1 when salinity was raised from 8.5 to 25%. The relative increase in O2-uptake across the skin following an increase in salinity was smaller than the increase in total O2-uptake. This is taken to indicate that the high O2-consumption of skin is not specifically related to an osmoregulatory function of the skin.