Direct carotid-cavernous fistulas (CCFs) are commonly treated using the transarterial approach with detachable balloons. Occasionally, Guglielmi detachable coils (GDCs) are used in patients with mild steal of flow. The fistula can be obliterated progressively after initial incomplete treatment. It is supposed the GDCs are not suitable for patients with severe steal of flow. We present a 54-year-old woman with high-flow CCF. Balloon embolization of the fistula was tried but failed via both transarterial and transvenous approaches. We used 19 GDCs to obliterate the fistula partially. The initial result was incomplete occlusion. However, complete occlusion of the fistula was found during the follow-up angiogram 2 months after the procedure was performed. We propose that GDCs can be used to treat patients with large, high-flow CCF with severe steal.