The embryonic SCs (ESCs) are pluripotent cells which can produce tissues of all embryonic germ layers namely, endoderm, mesoderm, and ectoderm. The adult SCs (ASC) are multipotent cells having the capacity to generate a limited subset of cells (Lodi et al., 2011). of The characteristic ability of the stem cells to renew themselves continuously for long periods and differentiate into specific cell types under appropriate conditions (Zhong, 2008) make them good candidates for cell-based therapies in regenerative or reparative medicine, especially to treat conditions such as diabetes, heart disease, rheumatoid arthritis, and several neurodegenerative diseases.Research on and application of ESCs for clinical use is a raging controversy. No regular human ESC therapies are available yet. According to the latest literature on the topic, the only on-going clinical trials employing ESC are being conducted on patients with spinal cord injury (Aznar and Sánchez, 2011). However, numerous trials have been/are being conducted with ASCs. Furthermore, therapies using ASCs have been available for years, e.g., bone marrow transplants. This article discusses some of the important clinical studies conducted with stem cells, specifically ASCs, and the results obtained pertaining to the efficacy and safety of such therapies.Myocardial infarction (MI) or the ischemic necrosis of the cardiac tissue occurs due to cardiovascular disease, leading to heart attack and causing damage to the cardiac tissue. The human heart muscle damaged by a heart attack does not heal naturally. The primary treatment protocol involves a rapid reperfusion of the infarct-related coronary artery in order to curtail the ischemic area and reduce tissue damage (Lodi et al., 2011). Also, angioplasty is required to be conducted soon after, to effectively reestablish the coronary flow. A new strategy of restoring damaged heart tissue is through facilitating the repair or regeneration of the tissue. Using ASCs as well as ESCs for heart muscle repair is, currently, an active area of research (stemcells.nih.gov).