Canine middle ear cholesteatoma is a disease with an aggressive biological behaviour and with clinical signs that may vary according to the degree of involvement of structures adjacent to the affected tympanic bulla and which may cause possible damage to the nervous system. This article describes 6 cases of canine middle ear cholesteatoma presenting different lesions and clinical signs diagnosed by Magnetic Resonance Imaging and confirmed by histologic or cytologic examination, with a review of the literature.