Laparoscopic surgery is a frequently used technique in surgery. But artificial pneumoperitoneum with CO₂ causes cardiovascular complication. We experienced two cases of cardiac arrests after gas insufflation. In first case, end tidal CO₂ concentration increased rapidly and then immediately cardiac arrest occurred. We performed cardiac resuscitation with epinephrine and cardiac compression and result in good recovery. A rapid rise in end tidal concentration is suggested as a useful early sign of CO₂ embolism. In second case, cardiac arrest occurred after gas insufflation, too. We used atropine and ephedrine but severe bradycardia and hypotension was not recovered. After removal of CO₂, heart rate and blood pressure restored. We found that flow rate of CO₂ was 50 L/min. The operation was started again, we used flow rate of CO₂ at 1 L/min. The operation was successful uneventfully. Slow insufflation combined with close monitoring is important to prevent cardiovascular collapse during laparoscopic surgery.