Twenty-three of 514 (4.6%) patients who underwent cardiac surgery in 1988 with cardiopulmonary bypass were later reoperated for sternal complications. Several risk factors, including pre-, intra and postoperative variables, have been investigated. A significant correlation was found with the presence of diabetes mellitus, the type of operation (bilateral internal mammary artery grafting), early reoperations, haemodynamic alterations, pulmonary infections and incidence of serious non infectious complications. The different sternal complications are analyzed from a clinical and therapeutic point of view.