A woman born in 1920 had had multifocal, yellowish nodules on her skin since childhood and had been given a diagnosis of pseudoxanthoma elasticum. When she was 59-year-old, a diffuse granular shadow was seen on a chest radiograph. When she was 74-year-old, she presented with dyspnea on exertion. A thoracoscopic lung biopsy was done. Histologic examination of the lung tissue revealed small calcified nodules scattered in the alveolar septa. Pseudoxanthoma elasticum is a systemic, hereditary disorder that usually affects elastic fibers of the skin, eye, and cardiovascular system. It's incidence is quite low: 1 out of 160,000-1,000,000 population. Very few cases of pseudoxanthoma elasticum with pulmonary involvement have been reported, and we know of no previous case in Japan in which pulmonary microcalcification was confirmed histologically.