BACKGROUND Reports of coexisting multiple intrauterine pregnancies and ectopic pregnancy are extremely rare. We present one case with early sonographic diagnosis of heterotopic pregnancy, successful laparoscopic treatment and a subsequent normal pregnancy course and outcome of the intrauterine twin gestation. METHODS A 29-year-old woman, gravida 1, para 0, presented for her first prenatal visit at 5 weeks of gestation with pelvic pain. She had conceived with 75 IU leutinizing hormone and follicle-stimulating hormone and homologous intrauterine insemination. The sonogram confirmed a dichorionic twin intrauterine pregnancy and left tubal pregnancy at 7 weeks of gestation. The patient underwent a laparoscopic left salpingostomy and removal of the ectopic pregnancy. Level II sonogram showed a grossly unremarkable twin gestation at 20 weeks. Labor was induced at 37 weeks of gestation due to mild preeclampsia and underwent vaginal delivery without difficulties. The first twin was a girl, weighing 2,722 g, with Apgar scores of 9/9. The second twin, a boy, was delivered 10 minutes later, weighing 2,863 g, with Apgar scores of 9/9. CONCLUSIONS Early sonography is essential for the diagnosis of heterotopic pregnancy, and timely surgical intervention can save the intrauterine twin gestation, with a subsequent normal pregnancy course and outcome.