A ruptured interstitial pregnancy combined with an intrauterine twin pregnancy is a rare and challenging problem. We present a 34 year-old nulliparous woman with a combined interstitial and intrauterine twin pregnancy after bilateral salpingectomy and in-vitro fertilization with embryo transfer (IVF/ET). An emergency laparotomy was performed because of internal bleeding at 7 weeks of gestation. A cornual resection was performed and the defect was successfully repaired. The intrauterine twin pregnancy progressed to term uneventfully. Obstetricians should be aware of the possibility of heterotopic pregnancy in women who conceive by assisted reproduction techniques. Early diagnosis and surgical treatment of this ruptured interstitial pregnancy permitted the development of the intrauterine pregnancy.