A long-term retrospective study of 300 patients who underwent fully endoscopic endonasal pituitary adenoma resection between November 1998 and October 2004. The patients' records as well as the data obtained from postoperative follow-up visits was used to determine outcomes. Additionally, the data were then compared to mean values calculated from several transseptal-transsphenoidal reports. From a total of 300 pituitary adenomas, 139 (46 %) were hormonally active, while 161 (54 %) were non-functioning. Mean follow-up period was 38.2 months. The average length of hospital stay (LOS) was 1.4 days. All patients had postoperative magnetic resonance imaging (MRI) studies to assess residual or recurrent disease; all patients with hormonally active tumors had additional postoperative hormonal studies. Remission, being defined as no hormonal or radiological evidence of recurrence within the time-frame of the follow-up, was demonstrated in 127/134 (95 %) of enclosed and 144/166 (87 %) of invasive adenomas. A comparison of fully endoscopic endonasal vs. transseptal-transsphenoidal remission results revealed an improved outcome using the fully endoscopic endonasal technique: ACTH (86 % vs. 81 %), PRL (89 % vs. 66 %) and GH (85 % vs. 77 %). The remission rate for non-functioning adenomas was 149/161 (93 %). Additionally, we noted a marked reduction in complications related to the endoscopic procedure. Our results conclude that the fully endoscopic endonasal technique is a safe and effective method for removal of pituitary adenomas providing more complete tumor removal and reducing complications.