Metastases to endometrium are a rare event. A case of a 53-year-old woman with a previous colon cancer presenting with a dysfunctional uterine bleeding is reported. The curettage specimens consisted of multiple fragments of proliferative endometrial tissue mixed with irregular glands, focally amputated, lined by very cells with elongated, hyperchromatic nuclei and solid sheets of neoplastic cells often filled with necrotic debris and inflammatory cells, resembling endometrioid adenocarcinoma. Neoplastic cells resulted positive at immunohistochemical reaction for CK20, CDX2, p53 and negative for CK7, vimentin, ER, and PR suggesting a metastatic colon adenocarcinoma. Absence of premalignant changes, such as hyperplasia, besides frankly malignant glands in an endometrial curette should be regarded as an alarming feature for a secondary nature mostly from large bowel. In these cases clinical history is crucial and an immunohistochemical panel made up of CK7, CK20, CDX2, p53, vimentin, ER, and PR is useful for the correct diagnosis.