Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has experienced an increased use in acute cardiac failure. There are some reports on negative effects of VA-ECMO on cardiac function, such as left ventricular (LV) dilatation and cardiac stun, but the support in the literature is scarce. This study investigates the effects of experimental VA-ECMO on LV function in both peripheral and central cannulation. Ten pigs were randomized to VA-ECMO by either peripheral cannulation through the femoral vessels or central cannulation in the right atrium and ascending aorta. Left ventricular performance was measured with pressure-volume catheters during 5 hours of VA-ECMO. The LV end-diastolic and end-systolic volumes increased comparably in both groups during ECMO. Left ventricular ejection fraction, stroke work, and maximum rate of pressure change decreased comparably in both groups as a function of time on ECMO. The site of cannulation had no impact on the LV response to ECMO. In conclusion, VA-ECMO increased LV volumes and reduced LV function, irrespective of cannulation site in this experimental model. Reduced LV ejection fraction and stroke work indicated LV dysfunction during ECMO.