We report a case of primary pulmonary classical Hodgkin lymphoma (CHL) in a 58-year-old woman. Twelve years ago, the patient complained of slight fever and weight loss. A mass of about 5 cm in diameter was seen in the right lung on radiography and computed tomography (CT). Right total pneumonectomy and resection of mediastinal lymph nodes were performed. A pathological examination led to a strong suspicion of Hodgkin disease (HD) (now referred to as CHL), but a definite diagnosis could not be made at the time. Six years later, a chest CT showed a tumor around the ascending aorta, which was treated successfully by radiation therapy. Six years later, the chest CT revealed a tumor in the anterior mediastinum. CHL was diagnosed based on an immunohistochemical re-examination of lung specimens resected 12 years earlier and CT-guided fine needle tumor biopsy specimens of the second recurrent tumor in the anterior mediastinum were compatible with the recurrence of CHL. Therefore, we diagnosed this case as primary pulmonary CHL that later relapsed in the mediastinum. The tumor size was reduced by radiation therapy and the patient is currently under observation as an outpatient.