Arterialization of orbital veins is most often due to dural arteriovenous malformations of the cavernous sinus area. We report an unusual case of unilateral proptosis (exophthalmos) caused by arterialized retrograde venous flow in the external jugular vein and cavernous sinus in a patient with an upper extremity hemodialysis fistula and ipsilateral acute central venous thrombosis. The patient's symptoms improved after surgical closure of the hemodialysis fistula.