Severely burned patients often show various degrees of organ failures, and when several vital organs are involved mortality becomes extremely high. A study was undertaken to elucidate the aetiology and clinical significance of multiple organ failure (MOF) in burned patients. One hundred and fifty-eight burned patients were analysed for organ failures in five vital organs or systems, the heart, lung, liver, kidney and blood clotting system. There were 91 organ failures observed in 34 patients, of which 26 had MOF. The most frequently affected organ was the lung, followed by the heart, kidney, liver and the blood clotting system. The mortality rate was 76.9 per cent in MOF and 1.5 per cent in non-MOF patients. Septicaemia was closely associated with the development of MOF. Also, inhalation injury and 'shock' were contributing factors to the morbidity. Five extensively burned patients had an early development of MOF without infectious foci and this type of early MOF was attributed to endotoxaemia possibly originating from the patient's own intestinal flora.