We report a case of inflammatory myofibroblastic tumor (IMT) arisen in the lung, a rare entity, in which surgical treatment was performed. The case involved a 15-year-old man who was pointed out a 5-cm sized tumor shadow in the right upper lobe of the lung by a chest x-ray film at a medical checkout when he had entered a high school. Following close exploration at the department of respiratory internal medicine in our hospital, he was referred to our department for the purpose of surgery with a suspicion of myofibroblastic sarcoma in the right upper lobe of the lung. Since the tumor was adjacent to the middle lobe and was an incomplete segment, right upper and middle lobectomy was performed. The histopathological diagnosis was IMT. However, the removed cells revealed metaplasia and p53 positive, indicating that his disease might be prone to recurrence and metastasis compared to usual IMTs. Thus further careful observation of the clinical course would be necessary. The postoperative course was uneventful and he was discharged from the hospital on the 13^th postoperative day.