A 66-year-old female developed exophthalmos, impaired visual acuity (perception of light), and diplopia one day after sudden onset of headache. Neurological examination revealed proptosis, chemosis, impaired vision, and ophthalmoplegia. Carotid angiography showed direct carotid-cavernous sinus fistula concomitant with an intracavernous aneurysm on the right side. Intraaneurysmal embolization using the Guglielmi detachable coils (GDCs) via the transarterial route was performed and complete occlusion of the fistula successfully achieved. The neurological deficits resolved completely by 6 months after embolization. Intraaneurysmal GDC embolization via the transarterial route may be an alternative for the treatment of direct carotid-cavernous sinus fistula due to rupture of intracavernous aneurysm.