Background: Direct surgical exposure and cannulation (DSEC) of the superior ophthalmic vein (SOV) can be used as an alternative approach for the endovascular treatment of cavernous sinus dural fistulas (CSDF) that fail conventional endovascular access. The aim of this study was to report the techniques, effectiveness and safety of DSEC of the SOV in these cases. Methods: Between June 2007 and June 2011, nine CSDF in nine patients who presented with ocular signs and symptoms were embolized using DSEC of the SOV when the CSDF could not be treated via the transarterial or transfemoral venous route. Results: All nine patients were successfully treated by introduction of Onyx in conjunction with detachable coils through the catheterized SOV to the affected cavernous sinus. No exposure or catheterization of the SOV proved difficult. Symptoms and signs resolved completely in all patients after successful occlusion of the CSDF. There were no intraoperative complications. All patients underwent follow-up cerebral angiography at least 3 months after treatment, and none showed recurrence of the fistula. Conclusion: DSEC of the SOV for embolization of a CSDF is a good alternative treatment when conventional venous routes are inaccessible. Surgical access to the SOV is direct and can be performed safely. The use of Onyx in conjunction with detachable coils is safe and effective for symptomatic CSDF.