In order to evaluate the influence of esophageal dysfunction on lung function abnormalities in progressive systemic sclerosis (PSS), we compared pulmonary function tests in 24 patients with PSS according to esophageal motility. We observed three groups of subjects with normal esophageal motility (8 cases), impaired peristalsis but normal lower esophageal sphincter (LES; 7 cases), and impaired peristalsis and LES function (9 cases). Dynamic lung compliance was significantly lower in patients with impaired peristalsis and LES function than in the two other groups, suggesting that a gastroesophageal reflux (GER) could enhance pulmonary fibrosis in PSS.