Ovarian pregnancy is a rare phenomenon. Its presentation often is difficult to distinguish from that of tubal ectopic pregnancy and hemorrhagic ovarian cyst. A patient had an ovarian pregnancy diagnosed following failed midtrimester therapeutic abortion in a suspected bicornuate uterus. Despite vaginal prostaglandin suppositories and intraamniotic instillation of urea and prostaglandin, neither the abortion process nor rupture of the ovarian pregnancy ensued. This is the first reported case of this most unusual presentation of ovarian pregnancy.