OBJECTIVES Radical retropubic prostatectomy (RRP) and radical cystectomy (RCx) are well tolerated and widely performed. Because intraoperative blood loss is one of the most common problems, we performed acute normovolemic hemodilution (ANH) to prevent allogenic blood transfusion (ABT). In this study we tried to clarify the safety, effectiveness and problems of ANH at urologic operations. METHODS The study included 169 patients who underwent RRP and 97 patients underwent RCx from April 2003 to March 2006. The eligible patients for ANH were required to have preoperative hemoglobin of 12 g/dL or more without history of myocardial ischemia. The amount of blood collected was 800 mL in RRP and 800 mL or 1200 mL in RCx. Neoadjuvant chemotherapy was performed in 11 (11.3%) of 97 patients with RCx. RESULTS ANH was available in 164 (97.0%) of 169 patients in RRP and 41 (42.3%) of 97 patients in RCx. All 11 (11.3%) patients who received neoadjuvant chemotherapy before RCx revealed anemia and all were excluded from ANH. No patients had an hypovolemic event develop during the autologous blood being stored. The median volume of intraoperative blood loss was 1400 mL in 164 RRP and 19 patients (11.6%) required ABT. In 41 patients undergoing RCx, the median volume of blood loss was 1720 mL and 13 patients (32.5%) required ABT. In the postoperative period, no patients had cardiovascular or pulmonary complications develop originated from ANH. CONCLUSIONS ANH is a safe and useful method of transfusion during RRP and RCx. ANH can be recommended for patients who need these operations.