We report a case of massive carbon dioxide embolism associated with injury to the inferior vena cava, during posterior retroperitoneoscopic adrenalectomy. The presenting clinical features were tachycardia, rapid oxygen desaturation and severe respiratory acidosis, without evidence of bleeding. The patient was resuscitated by increasing the fraction of inspired oxygen, administering intravenous fluid and converting to an open procedure to suture the vein. This case demonstrates that gas embolism due to vessel injury during posterior retroperitoneal adrenalectomy may arise without evidence of bleeding, severe hypotension or an abrupt increase in end-tidal carbon dioxide. Using a high carbon dioxide insufflation pressure in the retroperitoneal space enhances visualisation of the surgical field by decreasing small-calibre vessel bleeding. However, it can contribute to, and delay recognition of, carbon dioxide embolism. Knowledge of the clinical features of carbon dioxide embolism, careful monitoring and vigilance for intra-operative surgical challenges can assist with the detection of this rare but potentially fatal complication.