Cranial nerve dysfunction (CND) is not uncommon in patients with cavernous dural arteriovenous fistulas (cDAVFs), and may represent an initial manifestation or a complication after endovascular treatment. This study evaluated the outcome of CND associated with cDAVFs after transvenous embolization (TVE) using Onyx. Forty-one patients with cDAVFs were treated with TVE in our department between April 2009 and October 2013. For each patient, clinical and radiologic records were retrospectively reviewed and evaluated, with an emphasis placed on evaluating the outcomes of the pre-existing cDAVF-induced CND and the TVE-induced CND. Of the 41 cases, 25 had a history of preoperative CND. Postoperatively, gradual remission to complete recovery (CR) within 8 months was observed in 17 of these cases, transient aggravation in 7, and significant improvement to be better than preoperative function but no CR in 1. All aggravation of CND occurred immediately or within 1 day after TVE and resolved completely within 5 months. Nine patients developed new CND after TVE. New CND occurred during the perioperative period in 8 cases, but all cases resolved completely within 15 days-6 months. Delayed CND was observed in 3 cases with a time lag of 3-25 months after TVE. Two of these completely resolved within 20 days-1 month and the remaining case significantly improved. Both the pre-existing cDAVF-induced CND and the TVE-induced new or aggravated CND completely resolved in almost all cases after embolization with Onyx.