Stem cells are defined as cells that have clonogenic and self-renewing capabilities and differentiate into multiple cell lineages. Stem cells are found in all of us, from the early stages of human development to the end of life. According to differentiation potential stem cells are divided into 5 types: totipotent, pluripotent, multi potent, oligopotent and unipotent. They are vital to the development, growth, maintenance and repair of our brains, bones, muscles, nerves, blood, skin and other organs. Stem cell therapy is emerging as a potentially revolutionary new way to treat disease and injury, with wide-ranging medical benefits. The face of extradentary advances in the prevention diagnosis and treatment of human diseases, devastating illness such as heart diseases, diabetes, cancer and disease of the nervous system, continue to the primer people of health, independence and wellbeing has been revived in this study. Regenerative medicine is a multidisciplinary field concerned with the replacement, repair or restoration of injured tissues. This field emerged from the need for reconstruction in children and adults in whom tissue has been damaged by diseases, trauma and congenital anomalies. Stem cell research is a promising field with an alluring potential for therapeutic intervention, and thus begs a critical understanding of the long-term consequences of stem cell replacement. Stem cells have unrestricted potential to divide and this strength is used for the regeneration and repair of cells within the body during tissue damage. Research on stem cells is advancing knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms. This promising area of science is also leading scientists to investigate the possibility of cell-based therapies to treat disease. In our present review we tried to provide the information about stem cells and their significant role in regenerative medicine for treatment of various diseases. Key words: Stem cells, embryonic stem cells, adult stem cells, umbilical cord stem cells, regenerative medicine.