Management of the unanticipated difficult airway is one of the most relevant and challenging crisis management scenarios encountered in clinical anesthesia practice. Several guidelines and approaches have been developed to assist clinicians in navigating this high-acuity scenario. In the most serious cases, the clinician may encounter a failed airway that results from failure to ventilate an anesthetized patient via facemask or supraglottic airway or intubate the patient with an endotracheal tube. This dreaded cannot intubate, cannot oxygenate situation necessitates emergency invasive access. This article reviews the incidence, management, and complications of the failed airway and training issues related to its management.