INTRODUCTION Exophthalmia can be associated with several disorders. Although unusual, a carotid-cavernous fistula should be ruled out systematically as it may be associated with severe complications. CASE REPORTS We report three cases associated with both types of carotid-cavernous fistula that highlight the clinical presentation and diagnostic process. CONCLUSION A carotid-cavernous fistula should be systematically ruled out in patients with a uni- or bilateral exophthalmia. Careful examination with auscultation of the ocular globe contributes greatly to the diagnosis that may be confirmed by MRI or arteriography.