Endonasal or transnasal procedures are sometimes necessary in patients with head trauma. Before these procedures, the integrity of the skull base must be considered to avoid penetration of the cranial vault. A 54-year-old man was taken to a district hospital following a car accident. After the initial assessment and emergency treatment, he was transferred to our emergency clinic for further examination. The patient had massive nasal bleeding, though a Foley catheter had been inserted to control posterior bleeding. Computed tomography (CT) revealed that the catheter was not positioned correctly and was in the cranial vault. Several fractures of the maxillofacial and cranial bones and cervical vertebrae were detected on CT. He also had right hemothorax and bilateral brain contusions. Endonasal insertion of catheters or tubes in trauma patients without a complete assessment of the skull base can cause serious complications.