The case of a 30th week preterm newborn infant, ventilated because of hyaline membrane disease and presenting with localized stenoses of the carina involving both main-stem bronchi is described. The diagnosis was made on bronchoscopy and bronchography after a period of recurrent atelectases and lobar emphysema. Due to severe broncho-pulmonary dysplasia, surgical reconstruction was impossible. A balloon dilatation was successfully performed while the infant was still ventilated. He died however at the age of 180 days.