Human life begins as a single fertilized cell. As adult human beings we are profoundly complex. This journey from single cell to complex being is attributable to the role of stem cells (i.e. cells that produce all the different types of cells and tissues that make up the human body). Recent interest has focused on the development of stem cells as a therapeutic option in the treatment of disease. Due to their ability both to replace and/or repair damaged tissue, stem cell therapy provides an ideal means to improve therapy for cardiac disorders associated with heart muscle injury. In particular, pre-clinical studies in animal models of acute myocardial infarction have shown great promise for both repairing damaged cardiac muscle and generating new blood vessel formation in the infarcted area. Stem-cell research therefore holds great therapeutic potential and is relevant, not only to basic science researchers, but also to clinicians (who may need to consider such cell-based therapy in the future) and to their patients.