Amoxycillin-clavulanate was used in prophylaxis of infectious complications after abdominal hysterectomy. A group of 29 patients was treated routinely with metronidazol introduced vaginally 2-3 days before surgery. This group was compared with 40 patients who received two perioperative doses of Augmentin intravenously. The incidence of febrile morbidity, urinary tract infection, following antibiotic treatment and pelvic infection were followed in both groups. Patients in the amoxycillin-clavulanic acid group had significantly less infectious morbidity than those in the metronidazol group. The results suggest that antibiotic prophylaxis for abdominal hysterectomy is effective. The prophylactic agent should be bactericide against aerobic and anaerobic bacteria and non-toxic. Amoxycillin-clavulanate (Augmentin) meets all these criteria.