Pure lipomas of the uterus are very rare tumors that may be misdiagnosed on radiological examination due to their rarity and fat content. We present here the case of a 57-year-old postmenopausal woman who presented to the hospital with lower abdominal pain. Abdominal hysterectomy and bilateral salpingo-oophorectomy were performed under the prediagnoses of benign cystic ovarian teratoma or leiomyoma. On the histopathological examination of tissue samples, the tumor was composed of mature fat cells. There were a few smooth muscle cells confined to the periphery. Pure uterine lipoma may be asymptomatic or it may have symptoms similar to those of leiomyoma such as vaginal bleeding or pelvic pain. A pure lipoma should be diagnosed only if smooth muscle cells are confined to the periphery.