Several respiratory complications have been described in patients with ulcerative colitis (UC), and are the subject of this review. Involvement of the bronchial tree is the most frequent of them. Chronic bronchitis (16 patients) and bilateral bronchiectasis (16 patients) are responsible for chronic disabling bronchial suppuration. Symptoms related to the bronchial disease most often develop in patients in whom the diagnosis of ulcerative colitis is already established (88% of cases). Occurrence before the diagnosis of UC is possible, but unusual. Bronchial involvement can develop in patients whose UC is in complete remission, or who have undergone coloproctectomy up to several years earlier. Impressive improvement of cough and sputum production commonly occur following inhaled steroids. This is of great diagnostic and therapeutic significance. Other complications include subacute asphyxiating tracheal obstruction due to intralumenal inflammatory overgrowth (1 patient), small airways disease and panbronchiolitis (2 patients), BOOP (4 patients), pulmonary angiitis (6 patients), desquamative interstitial pneumonitis and granulomatosis (2 and 3 patients respectively), biapical pulmonary infiltrates (2 patients) and serositis. In addition, UC patients can develop less specific pulmonary problems such as pulmonary edema, pulmonary embolism and sulfasalazopyridine-induced pneumonitis and fibrosis.