Laminotomy as described by Réthi, and segmental tracheal resection with end-to-end anastomosis have proved useful in the adult for the treatment of stenoses of the larynx. In children, the question arises why these may interfere with the growth of the larynx and trachea. A vertical split of the cricoid cartilage followed by stabilization of the larynx by the temporary introduction of a Montgomery silicone T-tube was carried out on four kittens aged four to six weeks. A segmental tracheal resection with end-to-end anastomosis was performed on other animals of the same age. When the animals had stopped growing, the larynx and trachea were investigated both endoscopically and histologically. Following laminotomy the larynx underwent remodelling, resulting in an oval shape, the lumen being wide and the function of the vocal cords normal. Following segmental resection of the trachea, a circular stenosis was found, as a result of irregular growth of the sutured tracheal cartilages. In none of the animals, however were either functional disorders or respiratory distress to be observed. Thus, laminotomy or segmental resection of the trachea can be employed during the formative years without fear of clinically relevant growth disorders.