A new experimental model has been found whereby acute hemorrhagic pancreatic necrosis with fat necrosis is induced in 100% of young female mice fed a choline-deficient diet supplemented with 0.5% DL-ethioine. The onset of the pancreatic necrosis has been shown to follow accumulation, and subsequent activation, of pancreatic zymogens with intraparenchymal formation of significant amounts of elastase, chymotrypsin, and trypsin. Evidence was obtained that the proteolytic enzymes are released also in the circulation and cause a significant drop in the content of the serum protease inhibition alpha 1-antitrypsin and alpha2-macroglobulin. Increased levels of plasma amylase were found to accompany the onset of the pancreatic necrosis.