A 49-year-old female presented with proptosis and slight chemosis with diplopia on the right. The patient had a past history of skull base fracture occurring one year before the onset of the symptoms. Magnetic resonance imaging showed a partially thrombosed varicose aneurysm (varix) of the superior ophthalmic vein (SOV). Carotid angiography showed a pseudoaneurysm in the right cavernous sinus, associated with slow flow carotid-cavernous sinus fistula via the SOV. Proptosis was due to the direct mass effect of the thrombosed varix of the SOV. The thrombosed varix was removed after right carotid artery trapping with external carotid artery-middle cerebral artery (M₂) high flow bypass. The symptoms subsided after the surgery.