This manuscript[1] well described usefulness of endoscope-assisted microsurgery. Recently, endoscope is widely used such as aneurysmal clipping[2] and microvascular decompression[3] to make microsurgery safely. Posterior fossa tumor including epidermoid tumor is also good indication for endoscopic assistance.[4] Particularly the lower cranial nerve injury results in severe condition, which is dysphagia and hoarseness. Aspiration pneumonia is sometimes critical. To spare the cranial nerve is difficult but is important at the narrow operative view.However, to use endoscope has also risk at the narrow space. It is important to become skilled and master to use endoscope.I believe that endoscope-assisted microsurgery for the posterior fossa should be performed after mastering endoscopic usage for aneurysmal clipping and microvascular decompression.