A report is presented on a patient with acute aggravation of traumatic carotid-cavernous fistula after venography through the inferior petrosal sinus. After direct puncture of the internal jugular vein and insertion of the catheter tip to reach the inferior petrosal sinus, venography was conducted, but immediately thereafter bruit decreased and proptosis and chemosis increased. Though the fistula may have been occluded through the endarterial approach, the cause of acute aggravation is considered to have been thrombosis of the inferior petrosal sinus. The risk involved in venography or the transvenous approach for traumatic carotid-cavernous fistulas is discussed.