Carbon dioxide embolism is a rare but potentially fatal complication of laparoscopic surgery. The most common cause is inadvertent injection of carbon dioxide into a large vein or solid organ during initial peritoneal insufflation. We describe a case of carbon dioxide embolism in a 13-year-old boy during an elective laparoscopic cholecystectomy, caused by injection of carbon dioxide into a large paraumbilical vein. The clinical manifestations of carbon dioxide embolism were hypotension, bradycardia, and an abrupt drop in end-tidal CO2. He subsequently did well and had no sequelae. Carbon dioxide embolism is a recognized complication of laparoscopic surgery, although the risk to the patient may be minimized by the surgical team's awareness of the problem, continuous intraoperative monitoring of end-tidal CO2, and using an open technique for initial access to the peritoneum.