BACKGROUND The purpose of this study was to evaluate the visual outcome after extended endoscopic endonasal transsphenoidal surgery in patients with tuberculum sellae meningiomas (TSM). METHODS A retrospective analysis was performed for 12 patients (4 men and 8 women) with TSMs who underwent extended endonasal transsphenoidal surgery with pure endoscopy between 2003 and 2008. Neuro-ophthalmic evaluation was performed preoperatively and postoperatively. Visual acuity, visual fields, and funduscopy results were documented during the preoperative and follow-up periods. RESULTS There were three patients with bilateral optic foramen invasion and four patients with unilateral optic foramen invasion on radiologic findings preoperatively. Eleven patients had total tumor resection (Simpson grade I and II), and one patient had a subtotal tumor resection with a small asymptomatic tumor regrowth seen on magnetic resonance imaging at 14 months after surgery. Patients were observed for a mean follow-up time of 2.1 years (range 6 months-5 years), and the median was 28 months. Visual acuity improved in 92% of patients and was unchanged in 8% of patients. Eleven patients with visual field problems were better in various degrees at postoperative follow-up than before operation. No patients showed worsening of vision or visual field after surgery. CONCLUSIONS In this small, selected series with a relatively short follow-up, the extended endoscopic endonasal transsphenoidal approach to TSMs was a feasible alternative to the transcranial approach with minimal manipulation of the optic nerve. Procedures in the subchiasmatic space can be performed effectively with excellent visualization of the blood network supply to the optic apparatus while preserving the optic nerve in most cases.