We present a case of a 72 years old woman, non-smoker, who has been referred to our hospital due to dyspnoea on exertion and interstitial bilateral infiltrates on chest x-ray. Based on her medical history no typical symptoms of systemic disorder were reported apart from generalized aching. Clinical examination revealed symmetric joint swelling of knees and morning stiffness of hand joints for at least one hour. Moreover the rheumatoid factor was highly positive, whereas the x-ray of the hands indicated unequivocal bony decalcifications localized to the joints. The high resolution CT-scan of the chest revealed interstitial bilateral filtrates and three small (3-5 mm) nodules (rheumatoid nodules). Clinical and laboratory findings were consistent with rheumatoid arthritis which causes pulmonary fibrosis. It is a systemic disease which mainly affects the joints and other organs including the respiratory system. Pneumon 2003, 16(3):342-347.