In this prospective study, we report fifty consecutive cases of bilateral papilledema without neurosurgical or obvious ophthalmologic etiology, referred to our institution between January 2005 and March 2007. Lumbar puncture with opening CSF pressure measurement distinguished two groups of patients: Group 1 (n=39) with and Group 2 (n=11) without intracranial hypertension. In Group 1, 9/39 patients presented secondary intracranial hypertension mainly due to cerebral venous thrombosis. In 30 patients, after complete investigations, a diagnosis of idiopathic intracranial hypertension was made: as commonly reported, patients were predominantly overweight (96.7% with body mass index>25kg/m2) young (mean age=27.6 years) and women (96.7%). Eleven patients with intracranial hypertension had no headaches. In Group 2, the most common diagnosis was bilateral non-arteritic anterior ischemic optic neuropathy, but rare causes have been identified.