Conception in rudimentary horn is reported to cause severe obstetric and gynecological complications. Despite the crucial importance of the observation, there is an acute paucity of literature. Although, there are some reports available in the world literature, such a condition in Saudi population is very rare. In the present study a case report on pregnancy in rudimentary horn is presented and discussed. In this case, there was a left unicornuate uterus with a normal ovary and fallopian tube. To the right, there was a rudimentary horn, with a sac visualized on the surface. The sac ruptured with manipulation, expelled the fetus and placental pieces. Resection of accessory horn of the uterus was done with repair of resected segment of uterus. The patient had a smooth postoperative recovery. In conclusion, (1) it will be interesting to know, if history of previous caesarean sections for breech (as observed) might be a probable etiological factor for rudimentary horn pregnancies and (2) it is suggested that earlier detection of the location of embryonic growth by sophisticated diagnostic tools will save any such catastrophic outcome.