After severe craniocerebral trauma a 14-year-old boy developed progressive exophthalmos with venous congestion and chemosis, due to a direct caroticocavernous fistula. Angiography revealed traumatic occlusion of the ipsilateral internal carotid artery and absence of the inferior petrosal sinus. After failure of an approach via the anterior and posterior communicating arteries, the cavernous sinus was successfully catheterised through the occluded internal carotid artery, and embolisation performed with coils.