Background.Arteriovenous carbon dioxide (AVCO2R) removal is a technique of pumpless extracorporeal carbon dioxide removal. This system has been used successively to control pH and PaCO2in patients with acute lung injury who could not be adequately ventilated. This report describes the use of this technology in an organ donor awaiting harvesting.Methods.AVCO2R was implanted using a hollow-fiber oxygenator attached to 12 F and 14 F vascular cannulas that were inserted into the femoral artery and vein, respectively. Oxygen was attached to the oxygenator to provide the sweep gas.Results.The PaCO2and arterial pH promptly corrected after support was initiated (from 83–42 mm Hg and 7.18–7.38, respectively).Conclusion.This case describes the successful use of pumpless arteriovenous extracorporeal removal of CO2in a heart-beating donor awaiting organ harvest.