Sjögren's syndrome (SS) is an immunologic disease characterized by progressive destruction of the exocrine glands that causes mucosal and conjunctival dryness. In addition to the common pulmonary complications of diffuse interstitial lung disease, airways obstruction, desiccation of the upper respiratory tract, localized parenchymal nodules, recurrent tracheobronchitis, bronchiectasis, interstitial pneumonitis, and pleural effusion, patients with SS have a high risk of developing non-Hodgkin's lymphoma that may affect the lungs. Among 50 patients with SS and associated lymphoma, 10 had pulmonary involvement by lymphoma. The mean age of these 10 patients was 59.7 years, and 8 were women. The mean duration of SS was 7.2 years, and the mean interval between the onset of SS and lymphoma was 5.4 years. Cough and slowly progressive dyspnea were the most common pulmonary symptoms, and chest roentgenographic findings varied. Lung biopsies revealed a spectrum of low-to high-grade lymphomas, and high-grade lymphomas were associated with increased mortality. Of the 10 patients, 4 died from 8 to 48 months after lymphoma was diagnosed. We conclude that pulmonary involvement is common in patients with lymphoma associated with SS; thus, lymphoma should be considered in the differential diagnosis of pulmonary lesions in patients with SS.