This article describes a patient in whom significant oronasal bleeding developed after an injury to posterior superior alveolar artery of the maxillary artery in Le Fort I fracture.A 34-year-old man had a facial injury after an explosion of a furnace. Computed tomography demonstrated Le Fort I fracture, right open zygomatic tripod fracture, and open nasal bone fracture. Blood pressure, hemoglobin, and hematocrit levels had fallen to 110/60 mm Hg, 5.7 mg/dL, and 16.1%, respectively, 10 hours after injury despite continuous blood transfusion. Selective digital angiography confirmed an injury to the posterior superior alveolar artery, with extravasated pooling of contrast material in the maxillary sinus. The distal internal maxillary artery was embolized with n-butyl cyanoacrylate and lipiodol. Postembolization angiogram showed resolution of the contrast leak, and the patient's oronasal bleeding resolved.We suggest that if the oronasal bleeding continues in Le Fort fracture, bleeding from the posterior superior alveolar artery should be suspected. In case the vital sign is not stable, selective angiography should be performed before surgery.