In a present day surgery of paranasal sinuses endoscopic procedures have taken the lead over the standrad open procedures. ENT, head and neck surgery and neurosurgery are one of the main areas where the endoscope is used today. One of the main reasons is the large number of delicate anatomical structures, where in such cases the endoscope offers a more direct approach leaving many of them intact. Nonetheless, the percentage of postoperative comorbidites such as pain, oedema and haemorrhage, is substantially smaller in the endoscopic approach than in standard open procedures. Whereas open surgical procedures involves craniotomies, facial incisions, disruption of bone frames and tracheostomy, endoscopically assisted procedures usually use natural openings and corridors to get to the lesion, be it in brain, skull base, paranasal sinuses or any other location. In this graduate thesis we made a systematic review of endoscopic surgery by the technological advancement and the anatomical location. The first endoscope was used as early as the 19th century by the Italian physician Philipp Bozzini. Since then has undergone many modifications, of which the most significant is the introduction of the Hopkins rod lens system in the 1950s. Modern endoscopic surgery depends entirely on advanced radiological assessment and use of modern navigational systems, which use technology similar to that of GPS. The main disadvantages are the high cost of equipment and the relatively long learning curve before one can perform on his/her own. Endoscopically assisted surgery is an advancing field where many technological achievements may find their clinical application, as long as they are safe for the patient.