1. Between 1976 and 1986, data were collected prospectively by a nurse specializing in hygiene on postoperative infections in the 3508 low cervical cesarean sections carried out at the University Gynecological Clinic in Tübingen. Over the past four years, this has also included data on noninfectious complications. During this 11-year period, the rate of sections rose from 10.3% to 18.2%. 2. During the first seven years, in which only hygienic, organizational, and surgical measures were used to prevent infection, the rate of patients with postoperative infections decreased from 28.2% to 11.9% (-58%), while the rate of feverish standard morbidity decreased from 27.2% to 9.7% (-64%). 3. Over the past four years, in which 60% of the patients received a perioperative antibiotics prophylaxis consisting of three doses of a cephalosporin, the number of patients with infections has decreased further to 8.6% (-28%), and the number of those with feverish morbidity to 3.7% (-62%). Over the total period, the reduction in the named parameters was 70% and 86%. 4. The most frequent infections were urinary tract infections (mainly cases of asymptomatic bacteriuria), infections of the abdominal wound, and endomyometritis and phlebitis of the arm owing to intravenous applications. Only the reductions in the number of cases of bacteriuria (-77%), wound infections (-72%), and endomyometritis (-73%) reached statistic significance. 5. As a result of antibiotics prophylaxis, the rate of infections in the case of primary section decreased from 15.3% to 9.0%, and in the case of secondary section from 15.1% to 8.2%; feverish standard morbidity decreased from 9.1% to 3.5% and from 9.4% to 4.9%.(ABSTRACT TRUNCATED AT 250 WORDS)