Intraabdominal sepsis is frequently present after trauma, surgical resection, or intrinsic diseases of the gastrointestinal tract. When infection occurs it may be generalized or localized in intraperitoneal or extraperitoneal locations as well as in solid organs. The offending microflora is polymicrobial, consisting of both aerobes and anaerobes. Adequate, prompt surgical drainage and the appropriate choice of parenteral antibiotics aimed at both types of bacteria will result in a more favorable postoperative course and will reduce the possibility of local infection and secondary septicemia.