Since its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of microsurgical transsphenoidal procedures in the early 1970s. For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base. In this paper the authors review the history of the endoscope--its technical development and its application--from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented.