Idiopathic intracranial hypertension is a diagnosis most frequently made in young, overweight women. The chief hazard to the patient is permanent visual loss due to chronic papilledema. After the diagnosis has been clearly established using lumbar puncture and imaging techniques, the neurologist is involved in helping to lower the intracranial pressure, control the headaches, and encourage weight loss. Careful vision monitoring is essential and should be done in collaboration with an ophthalmologist. Visual fields, fundus photographs, intraocular pressure measurement, and visual acuity should be performed at each follow-up visit. The use of visual evoked response and repeated measurement of intracranial pressure by lumbar puncture do not provide data that help to guide therapeutic decisions. Indications for surgery are loss of visual field or decline in visual acuity in the fact of medical therapy, persistent headache, or the inability to perform visual-function studies. Optic nerve sheath fenestration and lumbar peritoneal shunt both appear to be effective surgical means to reduce the pressure on the optic disc. A neurologist and an ophthalmologist working together provide the evidence on which to base rational decisions in the care of the patient with idiopathic intracranial hypertension.