A 53-year-old woman was given a diagnosis of rheumatoid arthritis in 1988, and begun treatment with D-penicillamine in September 1992. She noticed dry coughing and exertional dyspnea that began in April 1993. Chest X-ray and CT films revealed no abnormal opacities. However, bronchiolitis obliterans was suspected because of a low FEV1% (23%). Examination of specimens obtained by thoracoscopic lung biopsy revealed constrictive obliteration by granulation tissue in proximal bronchioles and follicular bronchiolitis. Alveoli and respiratory bronchioles were intact. After corticosteroid and cyclophosphamide pulse therapy, FEV1% increased to 35%. At the time of this writing she was alive 2.5 years after hospitalization.