The objective of this study was to evaluate blood loss in patients undergoing radical retropubic prostatectomy. Blood loss and operating time were evaluated in a series of 197 consecutive patients with prostate cancer who underwent radical retropubic prostatectomy by a two-surgeon team. The patients were positioned supine with the table flexed and the patient in about 35 degrees Trendelenburg position. Results were compared with those recorded for an earlier series of 40 patients operated in the supine position alone. The influence of parameters that might affect blood loss (peridural and hypotensive anesthesia, bilateral hypogastric artery clamping) was assessed in multivariate analyses. Since adoption of a Trendelenburg position with flexion of the hips, the mean intraoperative blood loss has decreased by 80%, to a low level of 260 cc; and transfusions have become exceptional (0.5%). The decrease in blood loss correlated with a decrease in operating time, which was reduced to an average of 90 minutes. Whereas epidural anesthesia decreased blood loss by a modest 27%, intraoperative blood pressure, bilateral hypogastric artery clamping, and nerve sparing had little or no significant effect. Patient position and the surgical skill of a two-man team can virtually eliminate the risk of blood loss during radical retropubic prostatectomy. There is thus no need always to resort to other procedures or to preoperative autologous blood donation.