In 32 major burn patients, routine respiratory measurements and blood gases analysis were performed. Striking differences were found between survivors and nonsurvivors in these variables. Marked increases in minute volume and respiratory rate were observed in nonsurvivors starting from the 6th day postburn, while PaCO2increased with larger tidal and minute volumes. At the same time, PaO2was lower than in survivors. In survivors, the closing volume, maximum mid-expiratory flow rate, and peak flow rate were lower than the predicted normal values. This may indicate that after major burn injury, ventilatory power decreased and some pathological changes occurred in small airways and alveoli without apparent pulmonary complications. Marked differences in the changes of respiratory rate and min volume between survivors and nonsurvivors may indicate the value of simple respiratory measurements for prediction of outcome in burn patients.