Dark-blue pigmentation has been thought to be related to smoking or occupational exposure and has been regarded as anthracotic pigmentation. It is also frequently observed in non-smokers without occupational exposure, but there is no proven mechanism of pigmetation. To investigate clinical features and to find other causes of dark-blue pigmentaion, retrospective analysis was done in 59 patients who showed anthracotic pigmentation on bronchoscopy during recent 5 years in Seoul National University Hospital. The results were as follows; 1) Forty cases were non-smokers, while smokers were 19 cases. 2) Fifteen cases had history of tuberculosis, but there was no history of environmental exposure. 3) Mediastinal calcification was observed in 89.7%. 4) There was significant bleeding without exception when biopsy was done at the pigmentation site. 5) In patients with pigmentation only, hemoptysis and productive cough were main chief complaints, and chest X-ray showed atelectasis, infiltration, mass, or pleural change. 6) The number of patients whose lesion of X-ray corresponds to pigmentation site were 19/30 in tuberculosis, 4/30 in DILD and 7/30 in other diseases.