Mouth metastatic cancers are very rare and they usually represent the evidence of a widespread disease. Common primary tumors are lung carcinoma in men and breast carcinoma in women, followed by kidney cancer. In the oral soft tissues, the gingiva is the most common site, suggesting a possible role of inflammation in the attraction of circulating tumor cells. Oral metastasis has a serious prognosis. In this work, we describe the case of a 58-year-old man affected by renal cancer, who was brought to our attention for the appearance of a gingival swelling. Initially, the lesion was excised through a provisional clinical diagnosis of epulis. Subsequently, anatomopathological analysis showed a metastasis compatible with clear-cell carcinoma and specifically its renal origin was confirmed by immunohistochemical techniques.