Tracheal stenosis in adults usually is the result of mechanical injuries either from direct trauma or intubation. Rarely do cases develop in patients without such a precedent history, and there are few reports of the pathology of idiopathic tracheal stenosis (ITS). We reviewed clinicopathologically, 63 tracheal resections for tracheal stenosis in patients who had no antecedent explanation for their stenosis. We contrasted these 63 cases with 34 cases of tracheal stenosis owing to chondromalacia (CM) after mechanical injury. All 63 cases occurred in females, with a mean age of 49 years. The most common symptom was dyspnea on exertion. The average duration of symptoms was greater than 2 years. One-third of the patients gave a history of gastroesophageal reflux. All but one of the cases occurred in the subglottic region and/or upper one-third of the trachea. Pathologically, most cases showed extensive keloidal fibrosis and dilation of mucus glands, a finding that was not obvious in most cases of CM. ITS has relatively normal cartilage with smooth inner and outer perichondrium, whereas CM has extensive degeneration of cartilage with irregular border of inner perichondrium observable at shirt sleeve magnification. Immunohistochemical staining for estrogen receptor and progesterone receptor was positive in fibroblasts cells in most cases. ITS is a rare disease and restricted to females. It may represent some form of fibromatosis. ITS can be distinguished histologically from CM in tracheal resection specimens in most cases.