Pancreatic function tests, using a dual-tube technique and stimulating the pancreas with secretin and pancreozymin, were performed on patients with kwashiorkor (before and after treatment), marasmus, and chronic malnutrition as well as on a group of control children. The volume output from the pancreas, the pH of the juice and the enzymes amylase, lipase, trypsin, chymotrypsin, and ribonuclease were studied. The color index of the juice was also measured. The results demonstrated that the volume output and the ability to raise the pH of the pancreatic juice was not affected in the malnourished children. Patients with kwashiorkor and marasmus, however, had a grossly deficient enzyme output. There was complete and early restoration of pancreatic function after the initiation of dietary therapy in kwashiorkor and marasmus. The older chronically malnourished patients demonstrated a range of results varying from normal to abnormal. A significant positive correlation was demonstrated between enzyme output and the serum albumin concentration. There was no quantitative deficit in the output of bile among children with protein-calorie malnutrition.