Background & objectives: Acute pancreatitis (AP) in its severe form can lead to severe complications and death. Translocation of bacteria from the gut is one of the most important factors in the development of septic complications and mortality in acute pancreatitis. Oxygen-derived free radicals have been suggested to play a major role in the pathogenesis of AP. Xanthine oxidase enzyme is an important source of reactive oxygen metabolites. We undertook this study to evaluate the effect of allopurinol on bacterial translocation, oxidative stress and the course of AP in a rat model.