Uterine didelphys is a rare congenital anomaly of the female reproductive organs, designated by the presence of the uterus as a pair of organs. This occurs as a result of the failure of the embryonic fusion of Müllerian ducts. Women with this abnormality have a paired uterus with two cervices and usually a double vagina. The chance of having a pregnancy in one of the pairs along with prolapse of the other is very low in a didelphic uterus. To the best of the author's knowledge, only one case of such an event has been reported so far. In this case report, we are reporting on a 28-year-old gravida four para three (all are vaginal deliveries, 2 are alive, healthy, and term deliveries without any compilation; 1 is an early neonatal death delivered at 8 months) woman who presented to our hospital with a complaint of a protruding mass per vagina for 14 days in the presence of pregnancy. After she was evaluated and investigated, she was diagnosed with pelvic organ prolapse and late-preterm pregnancy. The prolapse reduced gradually as the gestational age advanced. Cesarean section was done at the gestational age of 38 weeks plus 2 days for the indication of infected pelvic organ prolapse in labor, with the outcome of a 3000 gram male alive neonate. Intraoperatively, there was uterine didelphys, one uterus holding the pregnancy while the other was prolapsing.