Painful ophthalmoplegia in childhood has different causes. One is Tolosa-Hunt syndrome, in which a first episode may be difficult to diagnose because of its clinical similarity to ophthalmoplegic migraine. A 10-year-old male with painful ophthalmoplegia and a cavernous sinus inflammation associated with an intracavernous carotid stenosis demonstrated by magnetic resonance imaging and angiography is reported. These findings resolved in follow-up imaging. This report suggests that in the presence of painful ophthalmoplegia, magnetic resonance imaging detection of cavernous sinus inflammation can facilitate the diagnosis of Tolosa-Hunt syndrome when other causes are excluded.