It is well known that autotransfusion can reduce or eliminate the use of homologous transfusion and can overcome the side effects of homologous transfusion. Also, many studies have been reported that autotransfusion showed better postoperative courses than homologous transfusion. We have reported the concept and benefit of autotransfusion in spinal surgery. So we would also compare the autotransfusion and homologous transfusion in total hip replacement arthroplasty, and would find out the effect of autotransfusion. From March 1993 to February 1995, autotransfusion group(38 hips) and homologous transfusion group(30 hips) were compared and eight patients(8 hips) who required homologous blood among autotransfusion group were excluded in comparison. The results were as follows: 1. Total transfusion amounts were 1013±174cc in autotransfusion group and 1088±601cc in homologous transfusion group. There were no statistically significed difference between both groups. 2. Total amounts and duration of postoperative drainage were significantly less in autotransfusion group, especially in the cases of postoperative autotransfusion with Orth-evac. 3. There was no difference of preoperative hemoglobin level in both groups, but the level was recovered more promptly in autotransfusion group. 4. In autotransfusion group, 3 hips(10%) showed fever and chilling sensation. Among them, 2 hips were transfused postoperatively with Orth-evac. In homologous transfusion group, 8 hips(27%) experienced one or more than one of transfusion side effects. 5. Homologous blood was also required in eight patients of autotransfusion group. Four patients of them were hypertensive and one was revision case. In conclusion, we think we can expect better postoperative recovery and also reduce or eliminate homologous transfusion with autotransfusion. But, hematologically and physiologically, further study will be necessary.