The case of a 68-year-old woman who presented with dyspnea and upper lobe pulmonary infiltrates and shortly thereafter developed seropositive, erosive polyarticular rheumatoid arthritis (RA) is presented. An open-lung biopsy to evaluate progression of infiltrates showed bronchiolitis obliterans-organizing pneumonia (BOOP). Both lung and articular disease responded rapidly to corticosteroid therapy. Interrelationships between BOOP, bronchiolitis obliterans, and interstitial fibrosis with connective tissue disease are discussed.