Pneumoconioses are still a common cause of chronic lung disease. The term »pneumoconiosis« refers to reactions of the lungs to inhaled mineral or organic dusts, and resultant alteration in their structure. The pathologic findings can resemble those of other fibrotic and granulomatous disorders in the lung. The knowledge acquired through research has been most valuable in determining the cause and pathogenesis of these occupational diseases. The toxicity, and hence fibrogenicity, of particulates is related to both the nature of the dust and the nature of the host response. Many of the dusts have a characteristic reaction pattern or appearance in histologic sections, which permits an accurate diagnosis. Others are associated with a reaction pattern that may suggest the diagnosis, but a careful occupational history and supplemental analytical techniques may be required to confirm the diagnosis. In industrialized countries, improvements in working conditions and dust controls measures have led to a decrease in the incidence of severe diseases of some »classic« forms of pneumoconioses, such as silicosis, coal workers’ pneumoconiosis, asbestosis. In recent years, a great progress in understanding, clinical characteristics, epidemiology and basic pathogenesis has been made in the field of metal-related parenchymal disorders. Although the particular substance or metal are the major contributory factors in the pathogenesis, not all individuals exposed to similar levels develop disease, thus suggests that there is a genetic predisposition to the development of pneumoconiosis. Therefore, it is crucial to identify the high-risk individuals to prevent the progress of the disease.