Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide; however, cases with metastasis to the oral cavity are extremely rare. Herein, we report a 68-year-old man who was diagnosed with HCC. Ten months after surgical removal of the right half of his liver, the patient developed gingival metastasis. Unfortunately, the patient died 4 months after the diagnosis. We discuss treatment options, pathological results, and disease prognosis. When a mandibular gingival mass is found, metastatic tumors should be considered in the differential diagnosis. In this regard, the patient's medical history and physical examination are valuable indicators for the diagnosis of mandibular gingival metastasis. This case provides a basis for the clinical diagnosis of metastatic HCC involving the oral cavity.