Intraabdominal sepsis most frequently follows penetrating or blunt abdominal trauma or perforated appendicitis or diverticulitis. The initial escape of the endogenous gastrointestinal microflora into the peritoneal cavity results in peritonitis and secondary septicemia, which is frequently followed by localized intraabdominal abscesses. These infections are most frequently polymicrobial and relate directly to the unique endogenous microflora at the various levels of the gastrointestinal tract. The treatment of intraabdominal sepsis is primarily centered around prompt, appropriate surgical intervention. parenterally administered antibiotics are also required to decrease the chance of local bacterial invasion or septicemia. The choice of the appropriate agent(s) to be used initially, before culture and sensitivity reports are available, depends primarily on the clinical presentation. Clinical and experimental studies of intraabdominal sepsis have largely stressed the use of antibiotic agents that have a spectrum of activity effective against both the aerobic coliforms and anaerobic Bacteroides fragilis.