Acute myocardial infarction causes irreversible loss of cardiomyocytes and endothelial cells compromising the cardiac function of patients. For some patients, current therapeutic approaches are not sufficient to prevent myocardial remodeling, which aggravates the disease. The potential of many types of adult bone marrow-derived progenitor cells in replacing damaged myocardium with functional cells has been investigated in several clinical and experimental studies. It has been demonstrated that these cells have an overall beneficial effect on heart function although the mechanism or multiple mechanisms involved have not been elucidated yet. Here, it will be reviewed some aspects of this fast-growing and controversial field of adult autologous progenitor/stem cells for cardiac repair.