19 subjects with an acute episode of pancreatitis, and 5 patients with chronic pancreatitis received intravenous glucose tolerance tests with measurement of glucose, insulin and glucagon. Patients recovering from acute pancreatitis demonstrated defects in their ability to dispose of a glucose load. 10 patients had overt glucose intolerance; of these, 4 were insulin-deficient, 3 had a loss of an acute insulin response to glucose, and 3 had marked hyperglucagonemia with normal to increased insulin levels. These abnormalities were seen in response both to intravenous glucose and intravenous arginine. Therefore, according to this study, at least three factors are clearly implicated in the production of glucose intolerance after an acute episode of pancreatitis: hypoinsulinemia, delayed insulin secretory response and hypergluca-gonemia.