Abstract General surgical complications after cardiopulmonary bypass (CPB) are infrequent but serious. No prospective studies have evaluated their incidence. We analyzed in such a study 135 patients who were to undergo CPB. Among these 135 patients, an abdominal complication developed in 6.6%; it contributed to 2 of the 5 deaths. Postoperative hyperamylasemia was found in 36% of patients, but only 2 had overt pancreatitis. The hyperamylasemia was not due to the salivary component, pulmonary complications, or prolonged CPB ( r = 0.22). A gastrointestinal hemorrhage occurred in 7 patients. No patients had acute cholecystitis. We conclude that abdominal complications are more frequent than reported in retrospective studies, and result in significant morbidity and mortality. Postoperative hyperamylasemia is common but usually is not associated with untoward morbidity or mortality.