Introduction: Rudimentary horn is a developmental anomaly of the uterus. Pregnancy in a rudimentary horn is rare. The Diagnosis of the rudimentary horn pregnancy is very difficult and needs high index of suspicion. Case: We present a case of pregnancy in a non-communicating rudimentary horn that was difficult to diagnosis in the 1st presentation. The diagnosis was suspected when the case did not respond to the medical termination of pregnancy by misoprostol; and also by mechanical methods. Following that a suspicion of an abnormally located pregnancy was made and confirmed by radiology modalities. Patient had surgical resection of the rudimentary horn. Conclusion: Despite recent advances in ultrasound, the diagnosis of pregnancy in the rudimentary horn remains difficult, and high index of suspicion is needed in these cases.