Laparoscopic surgery is replacing conventional surgical techniques for many common operation. CO₂ absorption is a problem associated with laparoscopic surgery. However, hypercarbia have been proved clinically safe with appropriate ventilatory changes. But most of the studies have been conducted during laparoscopic cholecystectomy, laparosopic gynecological surgery, and animal studies. Therefore, studies on the effects of prolonged pneumoperitoneun are lack. We experienced a case of severe hypercarbia after prolonged CO₂ pneumoperitoneum. It is important that repeated arterial blood gas analysis during and especially after prolonged pneumoperitoneum to find hypercarbia.