A 29-year-old male developed ptosis and progressive pulsating protrusion of the right eye, accompanied by conjunctival injection and tinnitus following a bicycle accident. MR angiography revealed dilation of both superior ophthalmic veins and facial veins. Right internal carotid angiography demonstrated right carotid-cavernous fistula (CCF) at the C3 portion of the right internal carotid artery with abnormal venous drainage. After right carotid balloon occlusion test had been performed, a detachable balloon was introduced into the right CCF while preserving the lumen of the right internal carotid artery. A left CCF, which was detected after closure of the right CCF, was also closed with a detachable balloon. Follow-up carotid angiographies showed complete closure of both CCFs and no abnormal venous drainage. After 1 year no abnormal physical manifestations, or abnormal neurologic signs or symptoms were present.