We describe herein various sonographic features of uterine leiomyosarcoma. Transabdominal scanning (TAS) revealed an image indistinguishable from benign leiomyoma, with evidence of degeneration. Transvaginal scanning (TVS) clearly showed the thinness of the myometrium, and the possibility of deep myometrial invasion was suspected at intraoperative open direct ultrasonography (ODU). A very high peak systolic velocity and a slightly increased diastolic component at the periphery of the tumor were evident with pulsed Doppler ultrasound. Thus, TAS, TVS, ODU and Doppler ultrasound will yield useful information for the physician attempting to evaluate the extent and vascularity of uterine leiomyosarcoma.