Fifty-two severely wounded patients, admitted directly from a battlefield or after surgical treatment in a war hospital, were treated in the Surgical Intensive Care Unit of the 'Sisters of Mercy' University Hospital in Zagreb during the 1991 war in Croatia. Considering the severity of the wounds, blood loss was not as severe as expected. This can be attributed to the nature of the injuries as most of the patients were wounded by fragments of explosive devices which cause less tissue destruction than military bullets. Low serum potassium levels, metabolic acidosis, low total protein levels and consequently low serum calcium levels correlated with wound severity. Low serum potassium levels were caused by its redistribution. Reperfusion liver injury was also present. Consumption coagulopathy was one of the characteristic disturbances in this type of injury. There was a relatively big difference between fluid input and output caused by fluid loss through drain sites and large open wound surfaces. The low mortality of the severely wounded was due to their young age and the well-organized military medical service which was developed from the civilian medical service in a short time.