We report here clinical and MRI findings of four children with idiopathic intracranial hypertension (IIH). Their chief complaint was headache. Three patients had papilloedema, and the other one showed the highest cerebrospinal fluid pressure (106 cm H2O) without papilloedema. In two cases, the symptoms disappeared after repeated lumbar punctures. At admission, MRI demonstrated empty sella in all the four cases. Regarding the optic nerves, there were more than two of the following three findings: distension of the perioptic subarachnoid space, vertical tortuosity and elongation of the optic nerve, and flattening of the posterior aspect of the globe. Follow-up MRI showed normalization of sella turtica and/or optic nerve findings in two of the three cases examined. MRI focusing on the optic nerves and pituitary gland may provide important clues for the diagnosis of IIH, especially those without papilloedema.