A 25-years-old male, current smoker, was referred to our department for treatment of the right pneumothorax due to pulmonary eosinophilic granuloma. He underwent thoracoscopic partial resection of the right lung. Immunostaining of the specimen revealed a lot of Langerhans cells positive for S 100 protein, suggesting active lesion. After cessation of smoking, no recurrence of pneumothorax or progression of disease have been observed for 13 months.