We have had some difficulties when we replaced endotracheal tubes because of accidental cracking or splitting. A new commercially available endotracheal tube replacement obturator (Mettro) enabled smooth and rapid replacement of endotracheal tubes, and we report some clinical applications when it was used.The obturator, 80 cm in length, 6.3 mm in diameter, is made of low-density polyethylene, the core of which is guide wired (Figure 1). A smaller one, 70 cm, 2.3 mm, is also available for pediatric use. It is flexible enough not to scratch the oral and tracheal mucosa, though the embedded wire prevents the obturator from kinking. The larger one has a cm scale on the surface that can indicate how far it is in the endotracheal tube or airway. The tip of the obturator is smoothly tapered off, which enables smooth insertion of the obturator into the endotracheal tube.When an endotracheal tube should be replaced with a new one, the obturator is placed into the endotracheal tube and 2 to 3 cm farther than the tip of the endotracheal tube, such that the tip of the obturator is in the trachea. The cracked tube is removed slowly while keeping the obturator in position. After removal of the older one, a new endotracheal tube is reintubated safely without laryngoscopy. The important thing is to keep the obturator in position. There is no possibility of esophageal intubation or unsuccesful reintubation. Tube replacement can be achieved even when usual laryngoscopy is impossible, such as intermaxillary fixation of the jaws, micrognathia or limitation of mouth opening.The obturator can be used for enlarging the nasal way when nasotracheal intubation is indicated and the nasal passage way is narrow. The obturator is placed through the nare in order to lead small nasotracheal tubes, which can enlarge the nasal way.These clinical trials indicate that the endotracheal tube replacement obturator is very useful for endotracheal anesthesia for oral and maxillofacial surgery, because damage of the endotracheal tubes is not uncommon during such surgery.