A 29-year-old G6 P3023 woman presented at 37 weeks' gestation with rupture of membranes and oligohydramnios. After informed consent was obtained, a successful external cephalic version (ECV) was performed. The patient went into spontaneous labor, but about 2h after the ECV, the umbilical cord prolapsed, necessitating cesarean section. Umbilical cord prolapse is a possible complication of ECV in patients with rupture of membranes and oligohydramnios.