Sjögren's syndrome is characterized by a decrease in exocrine gland secretion and the destruction of secretory tissue and cells, that is, salivary and lacrimal glands. Although patients with Sjögren's syndrome have chronic cough and sometimes sputum, we have little knowledge concerning the morphology of their airways. We performed morphometric analysis of goblet cells and bronchial glands and compared them with intraluminal mucus volume by measuring the mucus-occupying ratio (MOR) in the airways of patients with Sjögren's syndrome. A total of 6 nonsmoking patients with Sjögren's syndrome who had no significant prolonged airway infections (Group SG) (6 women, 55 ± 2 yr) were compared with four control patients with no pulmonary diseases (Group NL) (1 woman and 3 men, 64 ± 2 yr) and five patients with chronic bronchitis (Group CB) (1 woman and 4 men, 52 ± 5 yr). Autopsied lungs from 15 patients were used for morphometry by a digitazing computer. Area proportion of bronchial glands (gland %) to bronchial wall, goblet cell-occupying ratio to total epithelial layer (goblet %), and MOR were measured in central (3−8 mm in diameter) and peripheral airways (2 mm or less in diameter). Gland % and goblet % in central and MOR in peripheral airways from Group SG were significantly larger than those from Group NL: 15 ± 2 versus 6 ± 1% (p < 0.01), 6 ± 1 versus 2 ± 1% (p < 0.05), and 9 ± 2 versus 0.6 ± 0.3% (p < 0.05), respectively. Further, these values from Group SG did not significantly differ from those from Group CB. No significant differences in other parameters between Group SG and NL were observed, although MOR in central airways in Group SG tended to be larger. These findings suggest that Sjögren's syndrome induces hyperplasia of airway secretory cells, probably by a disturbance in the airway defense mechanism resulting from secretory abnormalities.