['The aim of this study was to determine if there is a direct relationship between the duration of cardiopulmonary bypass (CPB time [CPBT]) and postoperative morbidity and mortality in patients undergoing cardiac surgery.', 'Retrospective study.', 'Cardiac surgery unit, university hospital.', 'Five thousand six patients, New York Heart Association classes 1 through 4, who underwent cardiac surgery between January 2002 and March 2008.', 'All patients were subjected to CPB.', 'The mean CPBT was 115 minutes (median 106). One hundred thirty-one patients (2.6%) died during the same hospitalization. The postoperative median blood loss was 600 mL. Reoperations for bleeding occurred in 193 patients (3.9%), and 1,001 patients received 3 or more units of red blood cells. There were 108 patients (2.2%) with neurologic sequelae, 391 patients (7.8%) with renal complications, 37 patients (0.7%) with abdominal complications, and 184 patients (3.7%) with respiratory complications. Seventy-two patients (1.4%) had an infective complication, and 80 patients (1.6%) had a postoperative multiorgan failure. The multivariate analysis confirmed the role of CPBT, considered in 30-minute increments, as an independent risk factor for postoperative death (odds ratio [OR] = 1.57, p < 0.0001), pulmonary (OR = 1.17, p < 0.0001), renal (OR 1.31, p < 0.0001), and neurologic complications (OR = 1.28, p < 0.0001), multiorgan failure (OR = 1.21, p < 0.0001), reoperation for bleeding (OR = 1.1, p = 0.0165), and multiple blood transfusions (OR = 1.58, p < 0.0001).'] Is cardiopulmonary bypass duration an independent predictor of morbidity and mortality after cardiac surgery?