We prospectively analyzed the safety of the perioperative use of low molecular weight heparin (LMWH) for prophylaxis of thromboembolic complications after radical retropubic prostatectomy (RRP).Seventy-three consecutive patients received Enoxaparin, a LMWH compound one hour before RRP and then every twelve hours until hospital discharge. A mean of seven doses of LMWH were administered. A comparison was made with a control group of eighty-nine patients undergoing RRP without anticoagulant prophylaxis.Estimated blood loss was 515 AE 215 cc with LMWH patients and 611 AE 471 cc in controls. Total drain output was a mean of 318 cc with LMWH and 300 cc in controls. Seven percent of patients treated with enoxaparin developed a wound or operative site hematoma or lymphocele compared with none in the control group.LMWH appears to be a relatively safe means of prophylaxis for thromboembolic complications after RRP with no apparent increase in intraoperative bleeding or postoperative drainage. However, postoperative hemorrhagic complications or lymphocele formation are slightly increased. LMWH should be considered for prophylaxis of thromboembolic complications in high risk individuals but the associated morbidity does not support its routine use.