[Ger. and French summ.][long dash]The determination of haptoglobin in 31 cases of obstructive jaundice, 21 patients with virus hepatitis and 60 with cirrhosis gave the following results Values obtained in obstructive jaundice show a significant increase (P - 0.01); in hepatitis the values are significantly reduced (P< 0.01). A significant reduction of the haptoglobin level is found in cirrhosis of the liver (P 0.01). Determination of serum haptoglobin has only a limited significance in the differential diagnosis of jaundice. Increased levels indicate obstructive jaundice and exclude, with a high degree of probability, the presence of hepatitis. Reduced levels or absence of haptoglobin, however, point to acute hepatitis.