Multiple primary malignant tumors (MPMTs) refer to two or more primary malignant neoplasms that simultaneously or successively occur in one or more organs in the same individual. Cervical sarcoma concomitant with endometrial carcinoma is rare. A 46-year-old woman was admitted because of increased menstrual volume for 4 years and irregular vaginal bleeding with discharge for 6 months. The diagnosis of endometrial carcinoma at stage II was made on the basis of results of ultrasound, pelvic magnetic resonance imaging, and hysteroscopic curettage. Extensive total abdominal hysterectomy + bilateral adnexectomy + bilateral ovarian arteriovenous high ligation + pelvic adhesion separation + pelvic lymphadenectomy +abdominal aortic lymphadenectomy via the abdomen were performed. Postoperative diagnosis of cervical sarcomas with endometrial carcinoma in stage IIIC1 was made according to the results of pathology and immunohistochemistry. Six cycles of cisplatin-epirubicin-isocyclophosphamide treatment were provided after the operation. Most clinical manifestations of cervical sarcomas are abnormal vaginal bleeding. Use of preoperative imaging and hysteroscopy is difficult for diagnosing cervical sarcomas, and postoperative pathological examinations and immunohistochemical diagnosis are mainly used instead. The possibility of MPMTs should be considered for endometrial carcinoma, especially if the cervical lesion is larger than that of the uterine cavity.