Introduction and Importance: The benefits of anti-vitamin K drugs have been demonstrated in several indications; however, it is always counterbalanced by an increased risk of bleeding, that can occur in different areas. Facial hematoma is a rare bleeding complication to our knowledge, this is the first report of a rapidly expanding atraumatic facial hematoma secondary to vitamin K antagonist over coagulation. Case Presentation: The authors report the case of an 80-year-old woman with a medical history of hypertension, and pulmonary embolism after 15 days of immobilization following a hip fracture treated surgically 3 years earlier, who has been on vitamin K antagonist therapy since then, without any follow-up, came into our emergency department complaining of a sudden onset of progressive left facial swelling for one day, and vision loss in her left eye. Her blood investigations revealed a high international normalized ratio of prothrombin up to 10. A computed tomography scan exposing face, orbit, and oromaxillofacial area objectived spontaneously hyperdense collection in the left masticator space suggestive of an hematoma. An intraoral incision was done by oromaxillar surgeons, and drainage were performed with a favorable evolution. Clinical Discussion In this mini review, the authors aim to describe this rare complication and to insist on the necessity of regular follow-up with international normalized ratio values and early warning signs of bleeding to prevent such fatal complications. Conclusion: Immediate recognition and management of such complication is very important to avoid complications.