Purpose We present a case of upper airway obstruction in a patient with an unstable cervical spine fracture in a halo orthosis. We also describe the mechanism by which the obstruction occurred and identify features that predispose patients in a halo orthosis to upper airway obstruction. Case An 81-yr-old female presenting to hospital with an unstable cervical spine fracture was scheduled for spinal fusion. She was fitted with a halo traction device in a flexed position, and an awake tracheal intubation was planned. The patient's airway was topicalized and 1 mg of midazolam was administered. Her oxygen saturation dropped, and mask ventilation was difficult and insufficient. She then became unresponsive and pulseless.