Six patients developed severe, unexplained, chronic bronchopulmonary disease from 3 to 13 years after the onset of nonspecific inflammatory disease of the colon. All had chronic bronchitis, bronchiectasis was diagnosed in four, and an obstructive type of pulmonary dysfunction was noted in five. Four of the six, including the two with only chronic bronchitis, had no history of smoking. There was an initial correlation between the pulmonary symptoms and the intestinal disease, except in two patients who developed overt pulmonary disease following total proctocolectomy. The frequent occurence of extraintestinal lesions has suggested that ulcerative colitis and regional enteritis are systemic disorders. Chronic unexplained bronchopulmonary disease may be another infrequent complication in such patients.