Significant advances in our understanding of the pathogenesis and microbiology of intraabdominal sepsis have been made over the past 15 years. There has also been progress in various aspects of diagnosis and treatment of these infections. Computed tomography and ultrasonography have simplified the diagnosis of an intraabdominal abscess, and percutaneous drainage of abscesses has become an acceptable alternative to surgery. Novel surgical approaches have been tried, but their true role is not yet defined. A broader selection of less-toxic antimicrobial agents is now available as treatment for intraabdominal infection. The role of superinfecting pathogens is more clearly defined. Patients who would have died of this infection in a previous era now survive because of an array of supportive therapies.