We describe idiopathic laryngotracheal and upper tracheal stenosis in 49 patients with no other cause for their stenosis. Traumatic, iatrogenic, infectious, and specific inflammatory processes were excluded. Histopathologically dense fibrosis of keloidal type thickened the lamina propria and choked the ducts of mucous glands but did not destroy cartilage. Thirty-five patients were treated by single-stage resection and reconstruction: 29 by laryngotracheal resection with laryngotracheoplasty and 6 by cricotracheal segmental resection. Thirty-two patients achieved good or excellent results in respiration and voice, 2 needed annual dilations, and 1 required permanent tracheostomy.