Congenital cholesteatoma of the middle ear is a rare clinical entity that classically presents as a pearly epidermal cyst seen behind the normal tympanic membrane. Many otologists hve speculated on the pathogenesis of congenital cholesteatoma(lack of tympainc ring, epithelial inclusions resulting from invagination of otic capsule or from defective closure of the neural tube, metaplasia, epidermoid formation), but lack of further study has been due to the rarity of this abnormality. In this study, we reviewed 7 cases of congenital cholestetoma to determine its pathogenesis by analysing findings of operation and temporal bone computed tomography. This review supports 'Lack of tympanic ring theory(Aimi, 1983)' as proposed mechanism of congenital cholesteatoma, and strongly favors aberrant migration of squamous epithelium from a distant source in the genesis of congenital cholesteatoma.