An epiglottic cyst is a common form of laryngeal cysts which are rare causes of upper airway obstruction. A congenital laryngeal cyst always causes neonatal respiratory distress, but an acquired cyst shows very wide spectrum of symptoms such as no specific complaints, dysphagia, respiratory difficulty, or even death according to its size, location, or age. From anesthesiologists' point of view, an asymptomatic undiagnosed laryngeal cyst is a major concern. Unexpectedly, it can cause difficult airway such as 'cannnot intubate' or 'cannot intubate and cannot ventilate' situation during anesthesia. Recently we discovered an undiagnosed epiglottic cyst obscuring laryngeal inlet, leading to difficult intubation during general anesthesia for decompression and fusion of lumbar vertebrae. Fortunately, mask ventilation was possible, and after failed attempts of direct laryngoscopy, we could perform oral fiberoptic bronchoscope-aided intubation. He was discharged 10 days later with no harmful events.