A 69-year-old man consulted our department regarding further examination because abnormal venous ectasia of the basal vein of Rosenthal (BVR) was accidentally found on magnetic resonance imaging. Angiography revealed a dural arteriovenous fistula (DAVF) in the left sphenoid wing; the fistula was supplied by the ophthalmic artery and the middle meningeal artery. Venous drainage from the fistula consisted of a large collector vein located in the temporal tip, which drained into the BVR. We selected open surgery because this lesion may be difficult to access and is associated with significant risks through an endovascular approach. After temporal clip ligation of the drainer, the superficial middle cerebral vein became the main drainage route directly in connection with the fistula. Therefore, both were ligated, after coagulation of feeding arterial networks on the dura around the sphenoid wing. The patient experienced no complications from the surgical procedure, and postoperative angiography demonstrated obliteration of the fistula. DAVF in the sphenoid wing with deep drainage is believed to carry a high risk of hemorrhage or venous infarction because of the presence of Galenic drainage, varix, and cortical venous reflux. Treatment is strongly recommended even if the symptoms are minimal. Open surgery appears to be safe and often the best therapeutic option.