The present report describes a pilot project to apply the principle of minidose heparinization to patients undergoing prostatectomy, comparing a control group of 50 prostatectomies treated in conventional fashion to a study group of 43 prostatectomies treated with minidose heparinization. Results of the study indicate that perioperative minidose heparinization in patients undergoing prostatectomy is associated with longer hospitalization, greater need for blood transfusion, greater degree of immediate and delayed postoperative bleeding, and a higher incidence of "rebound" pulmonary embolization after cessation of heparin, than in patients treated in conventional fashion.