Idiopathic intracranial hypertension ((IIH) is characterized by increased cerebrospinal fluid pressure of unknown cause. It is predominantly a disease of women in the childbearing years. Although the cause of IIH remains obscure, it has become clear that loss of visual function is common and patients may progress to blindness if untreated. Diagnosis should adhere to the modified Dandy criteria and other causes of intracranial hypertension sought. IIH patient management should include serial perimetry and optic disc grading or photography. The proper therapy can then be selected and visual loss prevented or reversed. Although there are no evidence-based data to guide therapy, there is an ongoing randomized double-blind controlled treatment trial of IIH investigating diet and medical therapy.