Mechanical circulatory support devices have become essential in the management of acute hemodynamic compromise, providing rapid, minimally invasive augmentation of cardiac output in heart failure, cardiogenic shock, high-risk percutaneous coronary intervention, post-cardiotomy ventricular dysfunction, and refractory cardiac arrest. Unlike conventional ventricular assist systems, percutaneous mechanical circulatory support devices are designed for swift deployment through peripheral vascular access and are intended for short-term support. Advancements over recent decades have substantially broadened the range of these devices. They vary widely in mechanism of action, flow capability, insertion technique, and hemodynamic targets, allowing tailored support for left-, right-, or biventricular failure. Parallel to technological innovation, evidence from major trials and international registries has refined contemporary practice by characterizing hemodynamic benefits, procedural outcomes, and device-specific limitations. This review synthesizes contemporary knowledge on pMCS systems, their designs, physiological effects, clinical indications, and limitations.