Anesthesia for ankylosing spondylitis (AS) patients with difficult airway is of great stress to anesthesiologists. If tracheal intubation is not mandatory for general anesthesia, laryngeal mask airway (LMA) may suffice for adequate ventilation. Yet, in certain circumstances, no one can guarantee that LMA will reliably serve the purpose in surgical AS patients, especially in operations performed in the lateral decubitus position. We present here an AS patient with difficult airway scheduled for hip surgery. General anesthesia with sevoflurane conveyed by an LMA through spontaneous ventilation in the lateral decubitus position was planned, and the induction was smoothly done. Unfortunately, laryngospasm and oxygen desaturation occurred during the operation; the patient was successfully rescued by nasal intubation with a GlideScope in the lateral decubitus position without interrupting the operation.