A 74-year-old man with a history of lung cancer presented for right upper lobectomy. After induction of anesthesia, it was noted that the abdomen became progressively more distended. Soon afterward, there was a significant decrease in tidal volume. Ultrasonography of the lung showed no sign of pneumothorax at the anterior second intercostal space. However, the roentgenograms showed a massive right-sided pneumothorax and extensive pneumoperitoneum. Both the pneumothorax and the pneumoperitoneum were decompressed in the operating room, and the elective lobectomy proceeded as previously planned. The patient was extubated at the end of the operation, and there were no sequelae postoperatively.