To determine the incidence of airway disease in Sjögren's syndrome, respiratory function was evaluated in 13 patients with this disorder. Six patients had clear evidence of airway disease without overt evidence of loss of elastic recoil, and 7 patients had normal pulmonary function studies. Five of the 6 patients with abnormal pulmonary function studies had never smoked cigarettes. Of the patients with severe airway disease, all had exertional dyspnea but none had chronic cough with sputum production or recurrent bronchospasm. The 3 patients with the most severely impaired pulmonary function studies showed abnormal single-breath nitrogen curves, increased residual volumes, and hypoxemia, whereas static pressure-volume curves and maximal static elastic recoil at total lung capacity were within predicted norms. Lung biopsy of 2 patients showed mononuclear cell infiltration aroung narrowed small airways. We concluded that certain patients with Sjögren's syndrome develop an unusual type of chronic obstructive airway disease, which is probably a result of a chronic mononuclear cell inflammatory process similar to that seen in their salivary and lacrimal glands. The data suggest that human airways should be considered another target organ of Sjögren's syndrome. Earlier reports have stressed the association of a restrictive pulmonary defect with Sjögren's syndrome. Our data suggest that the restrictive pulmonary defect seen in patients with the complete variation of Sjögren's syndrome is probably the result of the associated connective tissue disorder, rather than the result in the sicca complex.