Cardiovascular disease is the leading cause of death in developed countries. Acute myocardial infarction (AMI) is the result of hypoxia leading to cardiomyocyte death. This causes loss of function of contractile tissue, which is replaced by non-contractile fibrous tissue affecting left ventricular ejection fraction (LVEF). One of the current approaches to recover LVEF after an AMI is focused on the search for functional cells to replace the dead tissue, via implantation in the heart of autologous progenitor cells with a regenerative capacity. This review classifies these cells into two types: a) non-resident cells and b) resident cells within the cardiac tissue. We provide an overall view of the various subpopulations and their markers, based, in animal and human models from the early pioneering work to the latest findings.