Tonsillar metastasis from neoplasms, including lung cancer, are extremely rare, and the prognosis for patients with tonsillar metastases is rather poor. We herein describe a case of long-term survival follow-ing radiation for lingual tonsillar metastasis from a bronchial adenocarcinoma. A 39-year-old male was diagnosed with adenocarcinoma of the right lung and was surgically treated. Four months after surgery, a mass arising from the lingual tonsil was noted at the root of the tongue and was pathologically diagnosed as metastasis from lung cancer. In addition, a computed tomography scan revealed a jugular lymphadenopathy, which was considered to be a metastasis from the tonsillar tumor. The tonsillar mass and jugular lymphadenopathy disappeared after external radiotherapy (50 Gy). The patient is alive without recurrence more than 8 years after treatment for tonsillar metastasis. This is the first report of successfully treated tonsillar metastasis from a malignant tumor.