Due to lack of suitable organ donors, future degenerative diseases and traumas could be treated with stem cell engraftment. To do this, large numbers of cells must be grown and maintained in culture. These cells must also be capable to differentiate into all the cells of the body. Embryonic stem cells fulfill many of the necessary criteria for clinical translation for use in therapeutic transplantation for a myriad of diseases. There are still many issues including immunological, cell cycling and differentiation that must be overcome for them to reach their potential use in the clinical arena.