Lung cancer is a malignant tumor that is often fatal. Vaginal metastasis of pulmonary adenocarcinoma is very rare. To the best of our knowledge, this is the second such report worldwide and the first one from Korea. A 67-year-old woman presented with cough, excessive sputum and dyspnea that she had sufferd with for the past one year and she had a palpable lesion in the vagina. Chest CT showed diffuse bronchial wall thickening involving the left main bronchus, the left upper lobar bronchus and the lingular divisional bronchus of the left upper lobe. There were multiple, various sized nodules in both lungs, of which the largest one measured about 1.0 cm in diameter. Both lung and vaginal biopsies were performed and the masses were diagnosed as adenocarcinoma. Immunohistochemically, the tumor cells were positive for cytokeratin 7 and TTF-1, but they were negative for cytokeratin 20. We present this case of primary lung adenocarcinoma metastasis to the vagina.