SYNOPSIS A series of 30 patients (28 females : 2 males) presenting with benign intracranial hypertension is reported. It is shown that the papilloedema may be resolved in as little as six weeks by the use of dehydration therapy. Evidence is presented that this method can restore to normal a visual acuity which is as low as 6/24 or even 6/36. It is concluded that surgery is never required in the management of this condition. It is strongly recommended that serial blind-spot measurements should be used routinely to assess the effectiveness of therapy. Fluorescein angiography has a place in diagnosis among a small proportion of these patients.