High resolution computed tomography (CT) is presently the most accurate technique to study the temporal bone. Nevertheless, there is no general agreement about its usefulness in pre-operative evaluation of chronic otitis media. Indeed, if we rule out some exceptions, CT is not fundamental for diagnosis which can often be obtained through an accurate otomicroscopy. The Otology Group in Piacenza applies the following absolute indications for pre-operative CT in chronic otitis media: 1) difficult otomicroscopy evaluation; 2) suspected petrous bone cholesteatoma; 3) dubious diagnosis; 4) suspect of malformations; 5) review of cases that had previously undergone mastoidectomy; 6) suspected intracranial complications and/or meningoencephalic herniation (in this case also a magnetic resonance imaging must be performed). With the exception of these specific conditions, pre-operative CT is useless in cases of simple chronic otitis. However, when a cholesteatoma is suspected, CT can provide the surgeon, particularly when inexperienced, useful, but not indispensable, informations. Pre-operative knowledge of these informations can allow a more accurate evaluation of the case, with a better planning of the surgical procedure, in order to ensure a more specific informed consent. Finally, the Authors point out the fact that surgeon must be able to interpret by his own the CT data to have a real advantage by this examination.