Small cell carcinoma of the endometrium is a very rare entity. They are very aggressive tumours, with a poor prognosis. They represent a clinical challenge because of a lack of a standardised treatment. We see here a case of a 67-year-old woman with a history of a lobular breast carcinoma, diagnosed in 2002. After presenting with postmenopausal vaginal bleeding in October 2014, she underwent a hysteroscopy-guided biopsy which revealed a metastasis of breast carcinoma. A hysterectomy and bilateral oophorectomy was performed because of uncontrolled uterine bleeding. The pathologic diagnosis was small cell carcinoma (SCC) of the endometrium. A surgical complete cytoreduction was achieved after the case being presented in a multidisciplinary tumour board. Pathologic results revealed metastasis from peritoneal implants of SCC on the endometrium, and metastasis in pelvic and para-aortic lymph nodes from serous carcinoma of the endometrium. A total of four cycles of adjuvant chemotherapy based on cisplatin (80mg/m² day one) and etoposide (100mg/m² day one, two, three) every 21 days was given. The patient experienced persistent disease and died 17 months after the diagnosis. SCC of the endometrium is a very rare and aggressive disease that requires an individualised multidisciplinary management.