Blood collected from the irrigation fluid used during TURP was retransfused in 17 patients. Of the 17 patients, 8 cases were also transfused preoperatively reserved blood. The weight of resected adenoma (g), resection time (minutes), the volume of salvaged blood (ml) of 9 cases who were transfused only salvaged autologous blood were 30.6 g, 63 min. and 355 ml, respectively, and those of 8 patients who were given both salvaged and preoperatively reserved autologous blood were 46.1 g, 78 min. and 703 ml, respectively. No patient was transfused homologous blood. Preoperative urine cultures showed contamination of bacteria in 12 cases (70.6%), and the blood concentrated from irrigated fluid was positive for bacteria in 2 cases (11.8%). Blood count (RBC, Hb, Ht) just after TURP, after blood retransfusion, at the next and the 7th day after the operation were compared to those of just before TURP (Blood Count Ratio). The ratio of the 9 cases who received only salvaged blood were 83.5%, 96.8%, 90.9%, 85.2% each and the ratio of the 8 cases who were transfused both salvaged and preserved blood were 86.9%, 102.6%, 101.4%, 97.5% each. There were no adverse effects due to the autologous blood retransfusion. CONCLUSIONS Retransfusion of salvaged autologous blood from the irrigating fluid of TURP was clinically safe and effective. No homologous blood was transfused in TURP when salvaged autologous blood with or without preserved blood was retransfused to the patient.