The urinary excretion of kininogen, kallikrein (total and active), and kinins were measured in 7 men with severe liver disease and ascites. The results were compared with a group of normal controls matched for sodium excretion. Significant reductions in kinin excretion were noted in the patients with liver disease which could not be accounted for by differences in age, plasma renin, aldosterone excretion or sodium excretion. Both active kallikrein and kininogen excretion were reduced suggesting that deficiencies of enzyme and substrate contributed to the kinin deficiency. The importance of kininogen in the physiologic regulation of kinin excretion in this clinical state is discussed.