Primary adenocarcinoma of the trachea is rare. We present a case that was successfully treated with radiotherapy followed by surgical resection. A 66-year-old man was admitted to our hospital because of cough, sputum and dyspnea. A chest CT film showed a tracheal tumor, and transtracheal biopsy specimen showed well-differentiated papillary adenocarcinoma. Other examinations excluded the diagnosis of metastatic adenocarcinoma from other organs. Since stenosis of the trachea was rapidly progressive, a tracheal stent was inserted to alleviate the obstruction. After radiotherapy, the tumor size decreased, after which surgical resection was performed. No recurrence had been observed 26 months after the operation.