Endoscopic nasal surgery has become the single major advance in the specialty of otolaryngology since the introduction of the operating microscope and middle ear surgery. The value of improved assessment of nasal and sinus pathology using the endoscope diagnostically cannot be overstated. Once pathology is better evaluated, therapy will at least be more appropriate. It is now possible to carry out such nasal surgery as polypectomy, antrostomy and turbinoplasty more accurately and more safely, as well as provide better postoperative care. The use of the endoscope has afforded a useful sub-cranial route for the repair of at least small cerebrospinal fluid leaks, while it is likely that such procedures as dacrocystorhinostomy will eventually be mostly performed using the nasal endoscope. Some orbital decompressions will also be suitable for medial orbitotomy via the endoscope. Additionally, assessment of the extent of extrusion of orbital contents after blow-out injury has been invaluable, as is evaluation of the posterior wall of the frontal sinus after frontal bone trauma. Functional endoscopic sinus surgery (FESS) has an undoubted place in the surgery of frontoethmoidal mucocoeles. While few oncologists would be sanguine about its use in the surgery of nasal tumors, it is still of great value in evaluation and biopsy. Although FESS confined to the osteomeatal complex in the presence of early sinus disease is almost certainly an advance, what is still not proven, is the place of endoscopic sphenoethmoidectomy in the treatment of chronic rhinosinusitis.