Post-traumatic cholesteatomas pose the medicolegal problem of determining the causal link between trauma and cholesteatoma. The author reports on an observation of an antro-attical cholesteatoma that occurred ten years after a fracture of the pars petrosa. The pathogeny of the different types of post-traumatic cholesteatoma is discussed. From a study of the literature, it is possible to distinguish between cholesteatomas of the external auditory canal which are revealed relatively soon after the trauma (less than 5 years), and cholesteatomas of the middle ear that can be revealed more than 10 years after the trauma.