A prominent mandibular angle is considered to be unattractive in the Orient. With recent increase of angle reduction via intraoral approach, it also has risks of injuries on the surrounding structures, especially vessels and nerve. We herein describe a simple method using intravenous tube rubber for prevention of bleeding in mandible angle ostectomy. After elevation of the periosteum, an intravenous tube rubber sutured with 2-0 nylon on one or both side was positioned deeply along the inferior border of mandible, and planned ostectomy was performed. The rubber was removed easily by pulling out the string. We experienced 21 cases of the mandible angle ostectomy using intravenous tube rubber from November 2008 to June 2009 and found no major complications. Intravenous tube rubber can cheaply and easily be obtained in the hospital. During ostectomy, the rubber protects the facial vessels and nerve from saw blade, and provides better visual field. Therefore, intravenous tube protection of facial vessel is a simple method to prevent massive bleeding or nerve injury in mandibular angle ostectomy.