Following informed consent, 226 consecutive patients scheduled to undergo abdominal hysterectomy entered a randomized double-blind clinical trial to determine the efficacy of ornidazole versus placebo in the prevention of postoperative infections. Postoperative abscesses occurred in 2 patients (1.8%) in the ornidazole group compared to 5 patients (4.4%) in the placebo group. Febrile episodes occurred in 6 patients (5.3%) receiving ornidazole and in 13 patients (11.4%) receiving placebo.