Venous gas embolism is a rare but serious complication of laparoscopic and endoscopic procedures. We describe the case of a 33-year-old woman with a strictured hepaticojejunostomy anastomosis who was treated with transabdominal endoscopic balloon dilation. During the procedure, she suffered a venous gas embolus with immediate cardiovascular collapse. After treatment with pressors, electrical cardioversion, and multiple aspirations of the right ventricle, the patient recovered fully. We reviewed all reported cases of venous gas embolism during endoscopy over the past 30 years and identified multiple risk factors. We suggest precautions to minimize future complications in patients at increased risk.