The inability to extend the head may be due to a blocked cervical spine or to any cervical instability imposing to maintain the head straight. Exposure of the glottis during intubation may be difficult and can be ameliorated by a stable general anesthesia, some pressure on the larynx and by charging the epiglottis. When mouth aperture is superior to 40 mm, a lighted stylet, a laryngoscope with a prism, a fiberoptic laryngoscope (Bullard) or the PCV laryngoscope represent a possible alternative to the Mac Intosh laryngoscope. If mouth aperture is superior to 20 mm but inferior to 40 mm, a ENT or PCV laryngoscope or a fiberoptic intubation are recommended. One should remember that the intubation is easier if the diameter of the ET tube is small. If the mouth aperture is inferior to 20 mm, nasal intubation (if intubation is indicated) is mandatory using fiberoptic intubation or a retrograde technique or even nasal blind intubation. In case of failure of intubation in a hypoxic patient, the anterior percutaneous route should always be kept in mind and transtracheal ventilation should be ready in case of failure, or even tracheotomy.