Comparative assessments of the endocrine and exocrine functions of the pancreas associated with gallstone pancreatitis or alcoholic pancreatitis were performed in a series of 86 patients, 20 with cholelithiasis, 12 with chronic alcoholism, 24 with chronic gallstone pancreatitis and 30 with chronic alcoholic pancreatitis and 32 healthy subjects were served as controls. The patients with cholelithiasis showed exocrine hypersecretion of the pancreas. In the patients with gallstone pancreatitis, all the assessed parameters of exocrine function were depressed. On the other hand, no pancreatic exocrine dysfunction was dispalyed in cases with chronic alcoholism. In the non-calcifying alcoholic pancreatitis, both the volume output and the the maximum concentration and output of bicarbonate were diminished but depression in amylase output was not seen. All these parameters were lowered in patients with calcifying pancreatitis. Elevation of hexosamine concentration in the pancreatic juice was evident in alcoholic pancreatitis as compared with gallstone pancreatitis, being particularly prominent in cases of non-calcifying pancreatitis. Patients with alcoholic pancreatitis were observed to secrete viscous pancreatic juice richer in amylase and hexosamine content, than those in the patients with gallstone pancreatitis. Endocrine dysfunction of the pancreas is more frequent and intense in alcoholic pancreatitis than in gallstone pancreatitis.