Middle ear cholesteatoma is a destructive lesion that can potentially erode the bone. Cholesteatoma is a clinical diagnosis in the vast majority of cases. Patients must be systematically investigated for the presence of signs suggestive of complications, the most common of which is labyrinthine fistula. However, the clinical features of labyrinthine fistula are inconstant and the fistula sign may sometimes be negative. CT scan of the petrous temporal bone is performed systematically to specify the site and extension of the cholesteatoma, and to assess the extent of osteolysis that can result in exposure of the membranous labyrinth. Surgical treatment has three main objectives: complete resection of the cholesteatoma, which is the only way to avoid residual cholesteatoma, prevention of recurrence by an adapted, preferably one-step, technique, and restoration of good quality hearing. Hydrodissection of the cholesteatoma matrix in the presence of labyrinthine fistula is a simple technique that can achieve the three main general objectives of cholesteatoma surgery.