The incidence of aerobic and anaerobic bacteria in the amniotic fluid and the cervix of 101 healthy parturients, with intact membranes, was studied. Pharynx, urine and umbilical cord of the newborns were also examined for the same pathogens. Although positive cultures from the cervix were found in 41.58% of the cases, the contamination of the amniotic fluid was only 1.98%. Our results support the view of the antibacterial activity of amniotic fluid.