A thorough assessment of the airway is fundamental in reducing the risk of an unexpectedly difficult intubation. Unanticipated airway problems account for 40% of anaesthesia-related morbidity and mortality. A careful airway assessment includes a detailed history, taking into consideration any previous difficult intubations and medical causes of a difficult airway. Patients require a comprehensive examination to evaluate the anatomy performing a variety of tests. These may include the modified Mallampati score, neck, and jaw movements, thyromental and sternomental distance and the upper lip bite test. Anatomical causes for a difficult airway could be due to a short, immobile neck, high arch palate, poor mouth opening or dentition, receding jaw or the inability to sublux the jaw. Further investigations as part of an airway assessment may involve indirect laryngoscopy, using flexible scopes, or imaging. A patient’s glottis and route to intubation may be examined using flexible scopes or videolaryngoscopy. Whilst, X-ray has been used in the past to evaluate mandibular anatomy and length to cervical processes as an indication of a narrow airway, computed tomography (CT) and magnetic resonance imaging (MRI) are now more commonly used. CT imaging produces fast high-resolution images including the lower airways and may be used for dynamic assessment in cases of intermittent airway obstruction. Moreover, the use of ultrasound to evaluate anatomical distances in the airway allows for radiological assessment.