Carbon dioxide (CO2) is insufflated into the peritoneal cavity to facilitate laparoscopic surgery because it does not support combustion and, thus, allows safe use of electrocautery. Any residual pneumoperitoneum at the end of the procedure is rapidly absorbed due to the high solubility of CO2 in blood. Massive amounts of CO2 are absorbed occasionally and can precipitate hypercarbic respiratory failure. We report a case of severe hypercarbia associated with subcutaneous insufflation of CO2 during laparoscopic cholecystectomy. Although the patient had cardiovascular disease, she experienced no serious consequences but did require postoperative mechanical ventilation.