Ruptured pregnancy in the rudimentary horn of women who have had a vaginal delivery is rare and unpredictable. However, when undiagnosed, this condition could lead to maternal morbidity and mortality. We report a pregnancy at 19 weeks gestation presented with acute abdomen and hypovolemic shock. She was initially thought to have an intrauterine pregnancy with the provisional diagnosis of a ruptured uterus. Intraoperatively, a ruptured non-communicating right rudimentary horn with ex utero pregnancy was discovered., Che Hasnura Che Hassan, Abdul Kadir Abdul Karim, Nor Azlin Mohamed Ismail, Mohd Hashim Omar, and Literatura 6