Tracheobronchopathia osteochondroplastica (TO) is a rare disease, although it probably occurs more frequently than expected. During an eight-year period, nine patients with TO were found among 2,180 performed bronchoscopies. There were four women and five men, with a mean age of 60 years. Cough, expectoration, dyspnea, hemoptysis, and recurrent airway infections were common, and most of the patients had had symptoms for more than ten years. Bronchoscopy revealed multiple yellow-white, hard, papilla-like formations reaching from the trachea to the segmental bronchi. Microscopy of biopsy specimens from the macroscopically altered mucosa showed osteocartilaginous tissue typical for TO in all patients. In eight of the patients spirometry showed an obstructive pattern.