We described a rare case of arteriovenous (AV) fistula after mandibular fracture in a 64-year-old man with chronic schizophrenia. The diagnosis was made by CT angiography. The patient suffered two episodes of mandibular fracture 3 months and 12 months ago. He was found to have a large AV fistula in left side of his neck. So the patient was scheduled for operation to correct fistula.