Stem cells are the cells in the body from which other cells with specialized functions are generated. They give rise to diverse mature cells, and have the capability to differentiate and self-renew. Stem cells have a significant potential to improve the function of damaged organs or tissues, regenerate biologically, and repair themselves. There are two types of cells, which can be used for cardiac repair, including somatic stem cells and allogeneic stem cells. The primary goal of stem cell therapies for heart diseases is to rebuild heart muscle and restore heart's function and structure. It can also be used for reducing the occurrence and symptoms of heart failure, repairing impaired myocardial cells, and improving the cardiac function. Cardiac cell-based therapies have been used with a range of cell types including peripheral blood progenitor cells, cells expanded through ex vivo culture, endothelial progenitor cells, and skeletal myoblasts such as embryonic stem cells (ESCs), stem cells, aspirated bone marrow cells and pluripotent stem cells (PSCs). This book explores all the important aspects of stem cells and their potential within regenerative medicine of the cardiovascular system. It will help new researchers by foregrounding their knowledge on stem cells.