Leiomyomas and diffuse uterine leiomyomatosis are smooth muscle tumors of the uterus. Diffuse uterine leiomyomatosis is a benign and extremely rare condition in which the uterus is symmetrically enlarged as a result of the almost complete replacement of the myometrium by innumerable poorly defined, confluent nodules. The etiology of these neoplasms is not completely understood. Initial symptoms of the diffuse uterine leiomyomatosis usually are abdominal pain and abnormal uterine bleeding. Similar to uterine leiomyomas, patients with leiomyomatosis present with menorrhagia, dysmenorrhea, abdominal pain, infertility, and pelvic pressure. Hormonal treatment usually fails to control the symptoms, anemia, or tumor growth after treatment is stopped. As a result, despite patients being in the third or fourth decades of life, hysterectomy has been the only permanent treatment option offered to patients for treatment of the symptoms related to uterine fibroids in diffuse leiomyomatosis. A case of a patient with a huge uterine mass (2.650 g in weight) who underwent hysterectomy due to diffuse uterine leiomyomatosis is presented together with a review of the literature.