Idiopathic subglottic stenosis is a narrowing of the trachea at the level of the cricoid cartilage of unknown etiology. It is a rare condition for which the real incidence has never been established owing to the difficulty of making the diagnosis. Although there is a female preponderance, no familial cases have been reported in the literature. We describe two pairs of sisters as well as a mother and daughter presenting with idiopathic subglottic stenosis. All known causes of tracheal stenosis were excluded, including prolonged intubation, surgery, autoimmune and inflammatory disorders, infection and gastroesophageal reflux disease. These are the first cases reported in the literature that suggest a genetic predisposition for idiopathic subglottic stenosis.