Pulmonary Langerhans-cell histiocytosis should be suspected in patients with nodular or cystic changes in the upper pulmonary lobes. Patients with Langerhans-cell histiocytosis usually have a history of smoking; lack of nicotine exposure or an age over 60 years makes the diagnosis unlikely. The diagnostic work-up should include a high-resolution CT of the chest as well as a bronchoalveolar lavage, bronchoscopic and/or surgical lung biopsy. Smoking cessation is the essential part of the treatment.