Regenerative medicine has become the most recent and innovative branch of the medical sciences. It deals with the restoration of damaged or injured tissues in patients suffering from catastrophic injuries or chronic diseases in which their own body’s regenerative capacities are not functioning properly. Regenerative medicine typically involves the study of stem cells and the engineering of biological tissues or organs. Stem cells are unique cells that have the capability of dividing continuously and differentiating into other end organ cells. Pluripotent stem cells and adult/somatic stem cells are the two main classifications of stem cells. They provide protection to injured tissues through cell differentiation, heterotopic cell fusion, and by the release of paracrine factors and exosomes. These methods work to limit inflammation, promote tissue restoration, and limit damage by reactive oxygen species. Principals of tissue engineering include the study of stem cells as well as the study and engineering of biological tissue scaffolds. 3D printers and bioreactors have been developed to facilitate the production of biologic tissues and organs for therapy. As technological capabilities increase, whole organs may be eventually engineered for transplantation into humans to combat chronic diseases and organ failure.