A 55-year-old man was admitted to our hospital with dyspnea on effort and sclerodactyly. The chest radiograph showed reticulonodular shadows in both lower lung fields. A diagnosis of systemic sclerosis was made based on the characteristic skin lesions, interstitial pneumonia and the positivity for anti-Scl-70 antibody. Surgical biopsies were performed, which showed various features characteristic of organizing pneumonia and non-specific interstitial pneumonia. Prednisolone and cyclophosphamide were given to the patient, but clinical symptoms and chest radiographic findings worsened. After cyclophosphamide was replaced with cyclosporine, his symptoms, chest radiographic findings and pulmonary function improved and stabilized. It is suggested that cyclosporine is useful for the treatment of progressive interstitial pneumonia associated with systemic sclerosis.