Intra-abdominal infection caused by a perforated hollow viscus, transmural bowel necrosis or pancreatic necrosis is a life-threatening illness. The cornerstone of surgical treatment is the elimation of the infectious focus, debridement and intra-operative lavage. In severe intra-abdominal infection secondary procedures, such as continuous postoperative peritoneal lavage or planned re-explorations are often done to prevent residual or recurrent infection. The patient benefit of these procedures in terms of morbidity and mortality is not evident. New therapeutic modalities such a intra-abdominal administration of fibrinolytic agents or anty-cytokine antibodies, which are primarily based on pathophysiological processes in the abdominal cavity following infection, may improve patient outcome.