Extracorporeal membrane oxygenation (ECMO) is a life support system often employed in place of mechanical ventilation. It supports the work of the heart and lungs during a period of critical illness and is most commonly used for conditions such as acute respiratory distress syndrome. Recently it has played a small but important role treating severe cases of COVID-19. The purpose of this illustration is to teach a broad clinical audience how ECMO performs decarboxylation and reoxygenation in a common two-site cannulation set up.