Endoscopic surgery has been performed in our Department since 1996 as assistance in micro-neurosurgical procedures. In the same way the endoscope was used in transsphenoidal pituitary surgery, but from the beginning of 2004 we started with "pure" endoscopic surgery. We present our experience with the first ninety patients to demonstrate our way of operating. Endoscopic pituitary surgery is performed through a natural nasal air pathway without any incisions. A 4-mm endoscope is placed in front of the tumor in the sphenoidal sinus and the tumor is removed with specially designed surgical tools. Postoperative nasal packing is not necessary and postoperative discomfort is minimal so the hospital stay lasts 3 days. The first control was after one month. There were eighteen recurrences of tumors.