Intracranial dural fistulas in the region of the cavernous sinus usually occur in middle-aged or elderly women in whom physical findings of ocular pulsation, orbital bruit, and ocular injection are subtle or absent. We examined a 19-year-old man with hemophilia who had a red, mildly proptosed left eye. Typical features of a carotidcavernous sinus fistula were absent except for the presence of dilated, tortuous episcleral vessels. Directional Doppler ultrasound evaluation detected retrograde blood flow in the left frontal vein and thus confirmed the presence of an arteriovenous shunt. After a selective internal carotid angiogram demonstrated a shunt from a dural branch of the internal carotid artery, the patient's symptoms remitted spontaneously. Directional Doppler ultrasonography is a noninvasive test that can detect the presence of a low flow, retrobulbar arteriovenous shunt in the region of the cavernous sinus.