From Nov. 1978 to Dec. 1988, autotransfusion was done in 25 patients, of which 23 suffered from traumatic hemothorax and 2 from spontaneous hemothorax. The amount of blood autotransfused was 500-2300ml (average 950ml). The time elapsed from accident was 5-44 hours (average 21 hours). Two patients had febrile reaction for a short period of time after operation. The rest recovered uneventfully. Hematological examination revealed that the quality of the blood collected from hemothorax was similar to that of the systemic blood of the patients and was superior to the stored blood. Free hemoglobin determination showed that 40% was in normal value (average 18.9%), and hemolysis was less serious than that of the blood after CPB. The results of aerobic and anaerobic cultures were negative. We believe that the quality of the blood collected from traumatic hemothorax was quite acceptable, and autotransfusion with such blood was adequate not only for war casualties but also for everyday emergency patients.