Clinically apparent carbon dioxide (CO₂) gas embolism is uncommon, but it may be a potentially lethal complication if it occurs. We describe a 40-year-old woman who suffered a CO₂ gas embolism with cardiac arrest during laparoscopic surgery for colorectal cancer and liver metastasis. Intra-abdominal pressure was controlled to less than 15 mmHg during CO₂ gas pneumoperitoneum. The right hepatic vein was accidentally disrupted during liver dissection, and an emergent laparotomy was performed. A few minutes later, the end-tidal CO₂ decreased, followed by bradycardia and pulseless electrical activity. External cardiac massage, epinephrine, and atropine were given promptly. Ventilation with 100% oxygen was started and the patient was moved to the Trendelenburg position. Two minutes after resuscitation was begun, a cardiac rhythm reappeared and a pulsatile arterial waveform was displayed. A transesophageal echocardiogram showed air bubbles in the right pulmonary artery. The patient recovered completely, with no cardiopulmonary or neurological sequelae.