Teratomas of extragonadal origin are extremely rare. The most common extragonadal site is the greater omentum. A 36-year-old woman was referred to our department for treatment of bilateral ovarian tumors. A 3- to 4-cm mass was observed in each ovary; bilateral ovarian mature cystic teratoma was diagnosed through imaging studies. The patient underwent single-port laparoscopic surgery, during which we found not only bilateral ovarian mature cystic teratomas but also an omental tumor macroscopically similar to the ovarian teratomas. The ovarian and omental teratomas were successfully removed through single-port laparoscopic surgery. The histopathological diagnosis of the omental tumor was parasitic mature cystic teratoma.