Postoperative sterno-mediastinitis is a life-threatening complication that occurs in about 0.75 to 1.4 per cent of all open heart operations. The result of treatment largely depends on timely diagnosis and appropriate surgical management. Risk factors for infection should be corrected preoperatively whenever possible. Among other preventive measures, meticulous asepsis, atraumatic surgical technique, preserving the blood supply and the mechanical integrity of the sternum, prevention of sternal instability, and correction of the same if it occurs are the most important. The management of sterno-mediastinitis should be tailored to the individual clinical features of the patients. Clearly cases with nonpurulent sternomediastinitis and no soft tissue or bone necrosis (type 1) may be treated with reopening, drainage, sternal stabilization, and primary closure. Virulent infections with tissue necrosis (type II) may be best handled with reopening, several days of open management, and debridement then secondary closure with viable tissue (usually muscle) flaps. Chronic, smoldering infections (type III) are usually managed with debridement and muscle-flap coverage.