Thirty-six patients with primary Sjögren's syndrome (pSS) and 60 healthy volunteers underwent provocative bronchial testing with aerosolized dosed methacholine. On the average, pulmonary functions tests performed before bronchial testing were normal. However, 18/36 patients (50%) had bronchial hyper-responsiveness (BH), an incidence higher that that found in our control population (6.6%). No difference between BH and normally responsive patients was found in the duration of disease, immunological abnormalities or symptoms, and only the FEF50 was significantly lower in the BH group. It is therefore hypothesized that in pSS bronchial hyper-responsiveness may be due to lymphocytic inflammation and an alteration in secretion secondary to gland damage.