A 70-year-old man was referred to our hospital complaining of left gingival tumors with bleeding, halitosis and impediments to eating and speaking. Tumors were also found in both lungs, the stomach, the intestines and the right adrenal gland. Biopsies of the gingiva and the stomach pointed to undifferentiated carcinoma. Although the patient was treated with carboplatin plus 5-fluorouracil, the gingival tumors did not change in size. Subsequently, the gingival tumors were irradiated with a total dose of 39 Gy, and disappeared completely. The patient died 78 days later of hemorrhage of the digestive tract. Postmortem examination revealed that the primary tumor was in the left lung. Nineteen cases of lung cancer metastatic to the gingiva have been reported. The prognosis in all was very poor, and the QOL was compromised. However, several cases have improved with therapy to the gingiva. We believe that initial therapy should be directed at metastatic gingival tumors of the lung.