This prospective investigation was undertaken to determine whether routine ultrasound visualization of the gravid uterus shortly before cesarean section would provide useful information in determining the site for uterine incision. Complete data were gathered on 124 pregnancies using a portable real-time ultrasound machine. Determination of the placenta and umbilical cord locations, fetal presentation, and amniotic fluid volume were reliable. Compared with a matched group without ultrasonic visualization, the eventual site for uterine incision and morbidity to the mother and fetus were not significantly different. Although routine visualization of the intrauterine contents before surgery is not necessary, worthwhile information may be gained in select cases to confirm a previously suspected noncephalically presenting fetus or a low anterior placenta.