In a study comprising 172 patients who had been abdominally or vaginally hysterectomised, the effectivity of short-term prophylaxis with cefotaxim on various infection parameters was examined. The 100 patients of the prophylaxis group showed a significant reduction (p less than 0.01) of postoperative fever and of pelvic infections after vaginal hysterectomies. With abdominal hysterectomies, wound infections and pelvic infections were not reduced so strikingly. Infections of the urinary tract were seen less frequently in the prophylaxis group. Perioperative short-term prophylaxis is meaningful in vaginal hysterectomies, whereas in abdominal hysterectomies such prophylaxis will be useful only in cases with enhanced risk of infection.