Because of the risks associated with arterial embolization of cavernous dural fistulas, we have sought an alternative method to promote fistula closure. Thirteen patients underwent transvenous embolization as a treatment for symptomatic cavernous dural fistulas. All procedures were performed from a femoral vein access through the inferior petrosal sinus or basilar plexus. In five patients the inferior petrosal sinus was not angiographically demonstrable; however, embolization was still possible through this route in two patients. The embolic agents used were detachable balloons in one patient, coils alone in five, coils and liquid adhesives in four, coils plus silk sutures in one, silk sutures alone in one, and liquid adhesives alone in one. Nine patients had follow-up angiograms, which showed complete obliteration of the fistulas and complete resolution of related symptoms. One patient had complete resolution of clinical symptoms but refused follow-up angiography. Another patient had 50% decrease in fistula flow on the follow-up angiogram and improvement in clinical symptoms. Two patients had complete fistula obliteration after embolization and progressive improvement in symptoms but follow-up angiograms had not been obtained. Follow-ups ranged from 1 to 97 months (mean, 15 months). Two complications were related to this treatment. An embolic stroke followed transient placement of a balloon in the internal carotid in one patient, and a second patient developed transient visual loss when the venous outflow pathways were occluded before fistula closure. The fistula was immediately closed with complete recovery of vision. With recent advances in microcatheter and embolic agent technology, transvenous closure of cavernous dural fistulas is now possible.(ABSTRACT TRUNCATED AT 250 WORDS)