Aims: The aim of this study was to investigate the clinical features and ultrasonographic findings of uterine carcinosarcoma (UCS). Methods: Seventy-five patients (mean age, 58.6 years) with pathologically proven UCS who were treated at our hospital from January 2003 to December 2015 were retrospectively recruited. The clinical features and preoperative findings on transvaginal sonography (TVS) were investigated. Results: Eighty percent of the patients were postmenopausal. The primary symptoms were postmenopausal abnormal uterine bleeding (57.3%), irregular menstruation (18.7%), vaginal discharge (10.7%) and the presence of a uterine mass or others (13.3%). The tumor marker CA125 was evaluated in 43 women and was found to be elevated in 15 (34.9%); in 60% of those women (9/15), the CA125 level was lower than 200U/ml. According to the frequency of the different types of lesions observed by ultrasonic imaging, we decided to categorize the lesions into 3 different groups as follows: Group I, intrauterine tumors (73.33%); group II, intra-myometrial tumors (13.33%); and group III, intra-endometrial tumors (13.33 %). Conclusion: Combined with the clinical features, the characteristics demonstrated by TVS provide evidence for an indication of the presence of UCS and could contribute to clinical decision-making.