Therapeutic embolization by means of transvenous copper wire insertion was performed in five patients with dural arteriovenous malformations (AVM's) of the cavernous sinus. In each case, angiograms had shown that the AVM's were supplied from both internal and external carotid arteries, which was thought to render complete transarterial embolization difficult. A No. 2.5 French Teflon catheter was introduced into the affected cavernous sinus through the superior ophthalmic or internal jugular vein with the aid of a flexible mini guide wire. Copper wires were pushed by the guide wire into the cavernous sinus until the disappearance or a sufficient decrease in the arteriovenous shunt was noted. The patients' symptoms resolved or improved without any severe complications. Angiography revealed complete disappearance of the lesion immediately after treatment in three cases and follow-up angiography taken within 8 months showed no arteriovenous shunt in any patient. This method is a promising treatment for dural AVM's when conventional transarterial embolization is thought to be difficult.