Idiopathic intracranial hypertension (IIH) is considered when evaluating a young patient with symptoms such as headache, transient visual obscuration or finding of palliedema. Lumbar puncture (LP) with opening pressure recording and cerebrospinal fluid (CSF) examination are required in patients with suspected IIH. Patients with IIH can have large variations in intracranial pressure (ICP), but rarely a single measurement of ICP is normal. Pathological conditions that resemble IIH clinically include cerebral mass lesions, hypertensive encephalopathy, hydrocephalus, and dural sinus thrombosis. Chronic forms of meningitis such as cryptococcal meningitis can resemble IIH initially because of headache and papilledema. Changes in visual acuity or visual-evoked potentials are signs of end-stage IIH-related optic nerve injury. Hospitalization is required when rapid visual loss or serious complications of IIH are suspected. Consultation with a neurologist, ophthalmologist, and neurosurgeon is indicated according to the severity of symptoms and the current treatment.