During the years 1964-1966, 47 patients with acute pancreatitis were treated with epsilon-aminocaproic acid. All the patients recovered. Another group, consisting of 41 patients, was during the same period treated with Trasylol. Two of these patients died. One had massive pulmonary embolism and pancreatic necrosis. The other had pancreatic necrosis and acute renal tubular damage. In a third group, consisting of 41 patients, only conventional treatment was used; three of these patients died. There were no statistically significant treatment-dependent differences. Use of antiproteolytic agents and heparin in combination is discussed.