A unicornuate uterus with a rudimentary horn is a uterine anomaly resulting from the incomplete development of one of the Müllerian ducts and an incomplete fusion with the contralateral side. Pregnancy in a rudimentary horn of the uterus is a rare clinical condition with a reported incidence of 1 in 100,000 to 140,000 pregnancies. Usually the diagnosis is missed and may present as an emergency with haemoperitoneum. The standard treatment is the surgical excision of the horn. A gravida 2, para 1 patient presented at 23 weeks' gestation with fetal demise. Repeated failed attempts at induction of labour raised the suspicion of an abnormally located pregnancy which was confirmed by magnetic resonance imaging. She underwent a laparotomy with right rudimentary horn excision. The final diagnosis of a non-communicating rudimentary horn pregnancy was made intraoperatively and was confirmed by histopathology. This case highlights the importance of an early ultrasound in detecting uterine anomalies and the need for high clinical suspicion.