Background: Cornelia De Lange (CDL) is a rare genetic syndrome characterized by short stature, intellectual disability, skeletal abnormalities, and distinctive facial features. We present a case of CDL with several rare cerebrovascular anatomic variants that impacted the treatment of a direct cavernous carotid fistula (CCF). Case Description: This 32-year-old male CDL patient suffered a direct, traumatic CCF on the left and presented to our institution for endovascular management. Cerebral angiography revealed several anatomic variants, including hypoplastic external carotid arteries bilaterally. The vascular territory typically supplied by the internal maxillary arteries was fed by a prominent vessel arising from the internal carotid artery (ICA) in the expected location of the vidian artery. This anatomic variant directly impacted management due to retrograde filling of the fistula, necessitating coil embolization at its origin from the left ICA. Conclusion: Advance knowledge of cerebrovascular variants associated with CDL may help interventionalists prepare to approach such cases. Additionally, further inquiry into the function of proteins encoded by genes associated with CDL could better our understanding of vascular development in the brain.