An 47-year-old woman presented for a microscopic vascular decompression with facial nerve palsy. Past medical history was noncontributory. There were not abnormal physical or laboratory findings. Oral tracheal intubation with an armored tube was performed without any problems. Anesthesia was maintained uneventfully in spite of a high peak inspiratory airway pressure (28 30 cmH2O). After surgery, she had symptoms of airway obstruction and the endotracheal tube was removed. The removed tube was found to have a protrusion through almost all the length of tube which reduced its internal diameter a half. Finally, in any case of "airway obstruction" in an intubated patient, we should consider mechanical problems. We should keep in mind the presence of an armored endotracheal tube cannot be regarded as a guarantee of a patent airway. We must test not only leakage of the cuff but also passage of the tube prior to usage.