Endometrial carcinosarcoma is a rare, aggressive disease, accounting for approximately 3% of all uterine neoplasms. The emergence of sarcomatous elements is considered the evolution of subclones arising from high grade endometrial carcinomas. Here, we report two cases of primary endometrial carcinomas recurring as carcinosarcoma. Case 1. a 58-year-old postmenopausal woman diagnosed to have a poorly differentiated endometrial endometrioid adenocarcinoma (FIGO stage IB) developed an intra-abdominal recurrence of disease after 17 months from diagnosis. Histopathological analysis documented a biphasic neoplasia consisting of an epithelial (grade 3 endometrial endometrioid adenocarcinoma) and a sarcomatous component. Salvage chemotherapy with cisplatin, ifosfamide, epirubicin, and then with taxotere was attempted. The patient died after 2 months. Case 2. A 56-year-old woman with a diagnosis of grade 3 endometrial adenosquamous carcinoma of the endometrium (FIGO stage IIIA) experienced pelvic recurrence after five months from completion of chemotherapy. Definitive histology was malignant mixed mesodermal tumor with focal areas of chondrosarcomatous elements. The patient was triaged to exclusive concomitant chemoradiotherapy and salvage chemotherapy. The patient died after 3 months. We describe two cases of high grade endometrial carcinomas recurring as carcinosarcoma, thus providing evidence that the metaplastic sarcomatous evolution is a very rare event which can occur in patients with anaplastic endometrial cancer.