In comparing two series of 72 operated cholesteatomas covered by a systematic surgical second look between 12 and 18 months, the authors have observed a distinct regression of residual cholesteatomas since oto-endoscopy came into use (from 47.7% to 10.7%). This new approach, with a minimum amount of practice, makes it possible to perform true endoscopy-guided surgery of the entire tympanic cavity, and reduces the indications of later tympanotomy.