Recombinant activated factor VII (factor VIIa) has prohaemostatic effects in bleeding patients with coagulation abnormalities. We aimed to test the hypothesis that recombinant factor VIIa could reduce perioperative blood loss in patients with normal coagulation systems. Therefore, we assessed safety and efficacy of this drug in patients undergoing retropubic prostatectomy, which is often associated with major blood loss and need for transfusion. In a double-blind, randomised placebo-controlled trial, we recorded blood loss and transfusion requirements in 36 patients undergoing retropubic prostatectomy, who were randomised to receive an intravenous bolus of recombinant factor VIIa (20 microg/kg or 40 microg/kg) or placebo in the early operative phase. Median perioperative blood loss was 1235 mL (IQR 1025-1407) and 1089 mL (928-1320) in groups given recombinant factor VIIa 20 microg/kg and 40 microg/kg, respectively, compared with 2688 mL (1707-3565) in the placebo group (p=0.001). Seven of twelve placebo-treated patients were transfused, whereas no patients who received 40 microg/kg recombinant factor VIIa needed transfusion. The odds ratio for receiving any blood product in patients treated with recombinant factor VIIa compared with control patients was 0 (95% CI 0.00-0.33) No adverse events arose. An injection of recombinant factor VIIa can reduce perioperative blood loss and eliminate the need for transfusion in patients undergoing major surgery.