Failure of fusion of one of the mullerian ducts with partial fusion with the opposite side results in the formation of a rudimentary horn with unicornuate uterus. If a pregnancy occurs in a rudimentary horn, result is usually a rupture either in first or second trimester and it is usually a life threatening condition. The phenomenon is quite a rare entity and there are very few reported cases. This specific instance is an example of a case in which a pregnancy of 16 weeks occurred in the rudimentary horn of a unicornuate uterus, resulting in a rupture. 

Keywords: Ruptured Ectopic Pregnancy; Rudimentary Horn; Unicornuate Uterus.