Sixteen cases of spontaneous carotid-cavernous sinus fistula treated in our clinic were angiographically classified into four types, based on the report by Barrow et al; Type A: direct shunts between the internal carotid artery (ICA) and the cavernous sinus (CS), Type B: dural shunts between meningeal branches of the ICA and the CS, Type C: dural shunts between meningeal branches of the external carotid artery (ECA) and the CS, type D: dural shunts between meningeal branches of both the ICA and ECA and the CS. Our fundamental modality of treatment for each type was described as follows; detachable balloon occlusion of fistula was performed for Type A immediately after the diagnosis was confirmed. On the other hand, conservative treatment was selected at first routinely for Type B, C and D with administration of hemostatic agents, control of the blood pressure and Matas test for a certain period. This selection was made because the latter three types sometimes showed a high rate of spontaneous regression of symptoms. Only when no improvement was obtained by conservative therapy with Type B, C and D, the following treatments were adopted respectively; Type B: irradiation----detachable balloon occlusion of fistula, Type C: embolization through ECA, Type D: embolization through ECA----irradiation.