Extracorporeal carbon dioxide removal (ECCO₂R) is increasingly used in clinical practice as a means of facilitating protective mechanical ventilation and reducing the risk of ventilator-induced lung injury (VILI) in patients with acute respiratory distress syndrome (ARDS). In some cases, however, ECCO₂R can worsen hypoxaemia due to various pathophysiological mechanisms that need to be taken into consideration. We report a case of refractory hypoxaemia that required interruption of ECCO₂R therapy.