Heterotopic pregnancy is the simultaneous presence of intrauterine and ectopic pregnancy. Although it is a very rare disease, the incidence of ectopic pregnancy is increasing as use of artificial reproductive technology increases. CASE 1; A 38-year-old twin pregnant nullipara woman with 6+2 weeks of gestation visited emergency room with abdominal pain and vaginal bleeding. Her current pregnancy was through in vitro fertilization-embryo transfer. On vaginal ultrasound, two intrauterine gestational sacs and left adnexal complex lesion were confirmed, and a large amount of fluid was confirmed in peritoneal cavity. She was diagnosed with heterotopic pregnancy and underwent emergency laparoscopic left salpingectomy. Of the twins with intrauterine pregnancy, one fetus missed abortion at 10+0 weeks of gestation, and the other was born full-term by cesarean section at 38+4 weeks of gestation. CASE 2; A 32-year-old primipara woman underwent intrauterine insemination after superovulation induction. she was visited to emergency room with abdominal pain and vaginal bleeding at 5+5 weeks of gestation. On vaginal ultrasound, four intrauterine gestational sacs (fetal pole and fetal heartbeat were confirmed in three sacs, but fetal poles were not seen in the other sac) and left adnexal complex lesion were confirmed, and a large amount of fluid was confirmed in peritoneal cavity. She was diagnosed with heterotopic pregnancy and underwent emergency laparoscopic left salpingectomy. Triple pregnancy, which was intrauterine pregnancy, was maintained as twin pregnancy by performing selective fetal reduction at 6+3 weeks of gestation. Twin fetuses were born full-term by cesarean section at 37+3 weeks of gestation. Even if intrauterine pregnancy is confirmed, the possibility of ectopic pregnancy cannot be excluded. Therefore, we recommend careful confirmation of adnexa through vaginal ultrasound even if intrauterine pregnancy is confirmed.