The use of percutaneous mechanical circulatory support systems in the setting of both high-risk percutaneous coronary intervention (PCI) and cardiogenic shock is an emerging, controversial issue in contemporary clinical cardiology. The most common devices are the intra-aortic balloon pump (IABP), the Impella and the extracorporeal membrane oxygenator (ECMO). Technical progress, equipment improvement and growing cath-lab team expertise are allowing to offer critical patients different levels of assistance according to the selected device. Indeed, they are extremely different and the selection of the proper device for each clinical scenario might be tricky. In high-risk PCI, mechanical hemodynamic support serves the purpose of preventing hemodynamic collapse during the procedure. According to baseline risk stratification, IABP or Impella are usually considered whereas ECMO is seldom considered as a third option for highly selected patients.Cardiogenic shock and cardiac arrest are still associated with high mortality rates. In these conditions mechanical support may be promising. The lack of benefit observed with the systematic use of the IABP (combined with the increased mortality associated with higher number of inotropic drugs) is actually prompting to increasingly consider Impella and ECMO use in critically ill patients. The development of multidisciplinary local protocols is considered pivotal to improve management and outcome of those patients requiring percutaneous circulatory support devices.