BACKGROUND: Carbon dioxide insufflation during an endoscopic thyroidectomy may cause an adverse effects on blood gas and hemodynamic status. This study was conducted to evaluate the safety of low pressure carbon dioxide insufflation during an endoscopic thyroidectomy. METHODS: Patients in ASA physical status I or II, scheduled for an endoscopic thyroidectomy (n = 70) were gathered for the evaluation. During the operative procedure, minute ventilation at a tidal volume 10 ml/kg and respiratory rate 10/minute was maintained. End-tidal carbon dioxide tension, blood pressure and heart rate were measured and compared before and at 10, 20, 30, 60 and 90 minutes after CO2 insufflation. RESULTS: End tidal carbon dioxide tension significantly increased up to 30 minutes and plateaued thereafter. Mean blood pressure significantly increased up to 30 minutes but there was no change in heart rate after CO2 insufflation. Complications were not reported. CONCLUSIONS: We concluded that low pressure carbon dioxide insufflation during an endoscopic thyroidectomy was safe and useful.