An association has been suggested between celiac disease and diffuse interstitial lung disease of the hypersensitivity pneumonitis type in several reports from Europe. The present report consists of a study of 18 North American, biopsy-proved celiac patients, who were compared with an equal number of control subjects balanced for age, sex, and smoking. The celiac patients showed no evidence of interstitial lung disease as assessed by chest roentgenograms and pulmonary function tests. However, a history of asthma or chronic cough was present in a higher proportion of the celiac than control subjects. Also the celiac patients showed objective evidence of airway obstruction, as demonstrated by differences between the two groups in FEV1 (P less than 0.05) and Vmax 50% and Vmax 25% (P less than 0.01 and less than 0.05, respectively). These results confirm a recent report questioning whether there is truly a relationship between celiac disease and interstitial lung disease. Nevertheless, our findings suggest an association between celiac disease and airway obstruction.