The rates of disappearance of intravenously injected amylase and lipase were determined in dogs before and after ligation of the renal vessels. Functional nephrectomy increased the half life of serum amylase from 5 to 14 hours and of serum lipase from 2 to 11 hours. Serum amylase values increased relatively little in dogs with a functional nephrectomy when enzymes were not infused. The increase in serum amylase activity was not correlated to the increase in serum urea nitrogen. The canine kidney was responsible for the disappearance of part of the amylase and lipase from the serum. Only trace amounts of either amylase or lipase activity were found in the urine. It is assumed the canine kidney inactivated these enzymes.