Subglottic stenosis is the most common serious long-term complication of endotracheal intubation in neonates and its pathogenesis is poorly understood. We describe the experience of one unit with 15 cases of subglottic stenosis requiring operative intervention seen over a 3-year period and review the pathology and pathogenesis of the condition. In 1 instance operative intervention was successful in treatment and avoided the need for long-term tracheostomy. A possible aetiological factor in at least 2 of the cases of subglottic stenosis was insertion of the wide shoulder of the endotracheal tube through the vocal cords. It is suggested that subglottic stenosis is due to reparative fibrosis following particularly severe acute intubation injury. Another factor may be delayed healing of the subglottic mucosa possibly exacerbated by full thickness cricoid cartilage necrosis. Although severe subglottic injury may occur at any time that the endotracheal tube is in situ, the most critical period is the first week of intubation.