Veno-arterial extracorporeal life support (ECLS) may be indicated in patients with refractory heart failure. The list of conditions in which ECLS is successfully used is growing and includes cardiogenic shock following myocardial infarction, refractory cardiac arrest, septic shock with low cardiac output and severe intoxication. Femoral ECLS is the most common and often preferred ECLS-configuration in the emergency setting. Although femoral access is usually quick and easy to establish, it is also associated with specific adverse haemodynamic effects due to the direction of blood flow and access-site complications are inherent. Femoral ECLS provides adequate oxygen delivery and compensates for impaired cardiac output. However, retrograde blood flow into the aorta increases left ventricular afterload and may worsen left ventricular stroke work. Therefore, femoral ECLS is not equivalent to left ventricular unloading. Daily haemodynamic assessments are crucial and should include echocardiography and laboratory tests determining tissue oxygenation. Common complications include the harlequin-phenomenon, lower limb ischaemia or cerebral events and cannula site or intracranial bleeding. Despite a high incidence of complications and high mortality, ECLS is associated with survival benefits and better neurological outcomes in selected patient groups.