The malfunction of an expiratory unidirectional valve (EV) can cause rebreath of expired gas, barotraumas, or ventilatory failure during the general anesthesia. The following is a report on a case of ventilatoryfailure caused by an EV that failed to open during the induction of anesthesia. A 57-year-old man was scheduled for the biopsy of a vocal cord polyp. After intubation, we could not detect the evidence of ventilation through the endotracheal tube. Suspecting the esophageal intubation, we administered extubation. The patient was still having difficulty in ventilating even after a retrial of intubation. Then we discovered the EV was failing to open properly with ventilation and thus not able to function properly. The common cause of ventilatory failure immediately after intubation is malposition of an endotracheal tube, like esophageal intubation, and equipment failure also has reported. Accordingly, we should remember possible causes of ventilatory failure after intubations and routine conscientious inspection of the ventilator.