Idiopathic intracranial hypertension (IIH) is a syndrome characterized by increased intracranial pressure of unknown cause, leading to severe headache, papilledema and visual disturbances. Its former name, pseudotumor cerebri, has gained popularity recently. The strongest and most consistent risk factors of IIH are obesity and female gender. Infrequently, IIH may present in the absence of papilledema showing a headache profile similar to chronic daily headache with migrainous features. There have been several proposed mechanisms to explain the etiology of this disorder associated with various clinical conditions. In recent years, some inflammatory factors, natriuretic peptides and aquaporins have been proposed as possible contributors of the pathogenesis. On the other hand, some investigators have reported that bilateral transverse sinus stenosis is seen in the majority of IIH patients; therefore, dural sinus stent placement is used in some patients. No single theory has been able to provide a comprehensive answer, and there is no consensus about the exact cause of IIH. The aim of this review was to discuss the new insights on the mysterious pathogenesis of IIH.