Background information on radiologic techniques and their application in the study of pneumoconiosis were discussed. A brief history of the development of x-rays and the hazards of excessive x- ray exposure were presented. Technical aspects of radiography and factors affecting image quality were described. Criteria for excellence in technical quality of chest x-rays were outlined. The major problems encountered in producing satisfactory films included: incorrect estimation of proper radiographic exposure, inadequate control of scattered radiation, unsatisfactory patient positioning, poor film screen contact, and failure to maintain minimum standards of cleanliness in the darkroom. The radiologic findings in pneumoconiosis and their progression were described. Inhalation of silicic materials usually resulted in radiographic opacities in the upper lung fields, while inhalation of other materials, especially asbestos (1332214) fibers, more commonly resulted in changes in the lung bases, which tended to be more irregular or linear in shape. Localized fibrous thickenings of pleural tissues which may become calcified were commonly seen in cases of asbestosis. Radiographic diagnosis was usually straightforward in advanced cases of pneumoconiosis, but radiographic findings in early cases were not unequivocally interpretative. The International Classification of Radiographs of Pneumoconiosis, designed to permit codification of pneumoconiosis cases was outlined and discussed. The importance of training of physicians and technologists in the production of high quality chest x-rays and their interpretation was emphasized. In addition to chest x-rays, other radiographic measures, such as tomography and bronchography were often useful in evaluating the nature and extent of pathological processes. The author concludes that radiologic procedures provide valuable diagnostic tools for the evaluation of dust related occupational lung diseases.