From 1990 to 1994 at Clinical Hospital Center, Zagreb, 1904 median sternotomies were performed for cardiac operations. Patients shared the same intensive care unit (ICU) with the wounded persons, admitted to the hospital from battlefield. Infection developed in 124 patients, an incidence of 6.51%. Methicillin resistant Staphylococcus aureus (MRSA) was isolated from 90, methicillin resistant Staphylococcus epidermidis (MRSE) from 19, and gram negative bacilli (GNB) from 56 patients, Pseudomonas aeruginosa in 2, and Clostridium pneumoniae in 1 case. Ninety-six patients (5.04%) developed superficial localized infection of subcutaneous tissues and they were treated with frequent dressing changes with antibiotic-soaked gauze in combination with systemic antibiotics. Twenty-eight patients (1.47%) developed mediastinitis and sternal dehiscence. They were treated by operative debridement followed by reclosure of the sternum with continuous antibiotic irrigation. We obtained satisfactory results with our method of closure of sternum which is a modification of Robicsek's technique. Nine of them required further operation. In seven cases we performed muscle flaps and in two omentoplasty. One hundred and twenty patients were discharged in satisfactory condition. The uncontrolled mediastinal sepsis caused death in 4 patients. Higher infection rate after median sternotomy during 1991 and 1992 could be possibly explained with the war circumstances in Croatia, and especially with MRSA strain becoming endemic in surgical ICU.