Due to the anatomical proximity between the skull and the face, maxillofacial trauma can often cause injuries to cranial structures. Among these complications are carotid-cavernous fistulas (CCF), which are rare in maxillofacial trauma, although their etiology is usually traumatic. They are described as an atypical communication between the internal carotid artery and the cavernous sinus, which can generate a sudden change in the direction and distribution of blood flow between the brain and orbit. This paper aims to report a case of craniomaxillofacial trauma in which the patient evolved with diplopia, palpebral ptosis, and ophthalmoplegia of the left eye, diagnosed as traumatic CCF. The oral and maxillofacial surgery and traumatology team of the University Hospital of Western Paraná was observed these symptoms for the first time during post-operative follow-up after one day of surgery to repair mandibular fractures of the patient in question. With the identifying the signs and symptoms, a neurosurgery was requested for assessment and management. After clinical evaluation and imaging tests, they diagnosed the condition as CCF 5 days after the mandibular fractures and the patient was referred for treatment. Surgery was performed, in the same day, to resolve the CCF with the endovascularly by embolization with micromoles. The CCF was resolved and the patient continued on outpatient follow-up, progressing without sequelae from the CCF or mandibular fractures.