Eighteen non-smoking women suffering from primary Sjögren's syndrome (pSS) with previously documented alveolitis were re-examined, clinically and by pulmonary function tests (PFT), bronchoalveolar lavage (BAL), chest X-ray and high-resolution computed tomography (HRCT) after a 2 yr follow-up period. Longitudinal evaluation revealed unchanged PFT. The final BAL study showed a normal differential count in six of 14 patients with initial lymphocyte alveolitis, and a persistent alveolar lymphocytosis in the remaining eight patients, associated with an increased percentage of neutrophils in one of them. In four patients with initial mixed alveolitis, the BAL cell profile was unchanged 2 yr later. Five of 18 patients (28%) had abnormal HRCT, represented by isolated septal/subpleural lines in three patients, ground-glass opacities with irregular pleural margins in one patient, and ground-glass opacities associated with septal/subpleural lines in another. All these patients had abnormal BAL results with an increased proportion of both neutrophils and lymphocytes. The presence of alveolar neutrophils was associated with a significantly (P=0.005) greater mean rate of reduction of carbon monoxide diffusing capacity (DLCO) -- more than four times the normal rate of loss of DLCO. Chest X-ray, repeated at the end of the 2 yr follow-up period, showed parenchymal abnormalities in only one patient who had evidence of fibrosis on HRCT. This study provides evidence that lung involvement is not an uncommon extraglandular manifestation of pSS and that a BAL neutrophilia may play an important role in the pathogenesis of pulmonary disease in this autoimmune disorder.