Congenital aural stenosis, as compared to congenital aural atresia, carries a much greater risk of cholesteatoma. In a review of over 600 patients with major congenital ear malformations, 50 patients (54 ears) were found to have congenital aural stenosis. Ninety-one percent of the ears in patients 12 years and older with a stenosis of 2 mm or less presented with cholesteatoma. Based on this review, the following opinions are given: 1. A bony ear canal opening of 2 mm or less puts the patient at risk of cholesteatoma formation; 2. the cholesteatoma is slow-growing; and 3. undiagnosed cholesteatoma will cause extensive damage to the ear by early adulthood. We recommend surgery for patients with stenosis of the external ear canal measuring 2 mm or less. The appropriate time for surgery is late childhood or early adolescence, before irreversible damage has occurred.