Congenital cholesteatoma is defined as cholesteatoma occurring behind an intact tympanic membrane (TM). In the middle ear, it has different stages according to its site and relation with surrounding structures. We report an unusual case which is congenital cholesteatoma in the oval window and posterior mesotympanum surrounding a dehiscent fallopian canal in a young adult without obvious lesion behind intact TM, discussing its management. We have focused light in an unusual case in our practice and concluded that early intervention in such cases is recommended to prevent complications and planning a staged surgery is the treatment of choice.