Carotid cavernous fistulae are an uncommon disease. They are classified as direct or indirect. In direct fistulas there is an abnormal communication between the internal carotid artery and the cavernous sinus. Indirect forms have an abnormal bypass between the meningeal branches of the internal and/or external carotid arteries and the same sinus. The purpose of this article is to provide an overview of the anatomy of the envolved area and the clinical findings, diagnostic evaluation and treatment.