Invasive mechanical circulatory support is the approach of choice in patients with acute myocardial failure resistant to conventional therapy. Today survival rates between 24% for postcardiotomy cardiac failure and 40% for bridge to heart transplantation can be achieved. However, a broad armamentarium of devices for mechanical circulatory support is necessary to provide optimum assistance for the failing heart in the various clinical situations. The available devices and their potential indications and limitations are reviewed.