The aim of this study was to investigate the influence of omega-3 fatty acids (omega 3FA) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. The induction of ANP resulted in significant increases in mortality rate, intestinal permeability, bacterial infection in pancreas and extrapancreatic organs, and serum activity of urea and amylase, alanine transferase (ALT), interleukin (IL)-6, tumor necrotizing factor-alpha (TNF-alpha), lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in the pancreas and lung, and a considerable decrease of concentrations of calcium, protein and albumin. The use of omega 3FA reduced mortality, phenol sulfophthalein excretion in urine, bacterial infection in pancreas, liver, spleen, MPO and MDA levels in pancreatic and lung tissue, LDH level in BAL fluid and serum IL-6 and TNF-alpha values. Serum triglyceride increased only in the omega 3FA groups. Serum amylase, ALT, calcium, urea, protein, IL-1, and degree of pancreatic damage indicated no difference between the pancreatitis groups. Increased intestinal permeability and cytokine levels, and free radical damage play an important role during the course of acute pancreatitis. The treatment with omega 3FA improves these effects. omega 3FA may be useful in the treatment during ANP in rats. Therefore, it can be beneficial in patients with pancreatitis. Copyright (c) 2006 S. Karger AG, Basel.