We report our preliminary results of pulmonary imaging by digital tomosynthesis, and describe some advantages of these digitally processed longitudinal tomographic images. Digital tomosynthesis of the lung was performed in 60 subjects, including 56 patients with a localized lesion or diffuse disseminated lesions, with a fluororadiographic TV unit with linear tomographic capability, in conjunction with an image processing unit. Dual energy subtraction digital tomosynthesis was also available in our system. Multiple longitudinal tomographs of the lung, which were reconstructed from a single set of tomographic image data, facilitated easy evaluation of the morphology of pulmonary abnormalities together with related broncho-vascular structures located in the same longitudinal plane as the lesion, and were immune from any problem caused by inconsistent depth of respiration. The image quality of the reconstructed tomographs was greatly improved by digital image processing to reduce tomographic blur and enhance image clarity. Dual energy subtraction digital tomosynthesis was effective in clearly showing the size, configuration, and distribution of calcification in the lesion. Digital tomosynthesis provided useful information in making the roentgenologic diagnosis of pulmonary lesions.