Congenital anomalies of the Mullerian system are estimated to occur in 0.1–0.3% of the female population (1). Even more uncommon is the occurrence of a unicornuate uterus with a rudimentary uterine horn, caused by the failure of development of one Mullerian duct. The true incidence is hard to determine because patients may never develop gynaecological or obstetrical problems. We present the case of a fifteen-year-old virgo intacta who presented with right iliac fossa pain and was found to have this anomaly at laparotomy.