Posttraumatic aneurysm (pseudoaneurysm) although are described extensively, occur infrequently in clinical practice, being them found with most frequently after surgical procedure such as osteotomies and TMJ surgery; this vascular disease also occurs regularly in wounds caused by projectile of firearm, and be originate weeks or months after the trauma.In the following case report of early onset pseudoaneurysm of the internal maxillary artery, which is quickly diagnosed by a high clinical suspicion of vascular injury and performing selective carotid angiography confirmed the diagnosis of pseudoaneurysm of almost immediate appearance.This patient is successfully treated with embolization coiling and had no complications after the procedure.