Although a bronchospastic attack is common during the induction and emergence of general anesthesia, it is quite rare during maintenance of it. We experienced a severe case of a bronchospasm in a male patient during the maintenance of general anesthesia. His past medical history indicated no risk factors for the bronchospasm except for heavy smoking. He suffered from poor ventilation, hypercarbia and a pneumothorax that occurred abruptly, 2 hours after inducing general anesthesia. Ten hours later, he recovered his normal respiratory function without any respiratory complication. This case highlights the possibility of a bronchospasm during the maintenance of general anesthesia.