Cell therapy is one of the most promising future techniques in the medical arsenal for the repair of damaged or destroyed tissue. The diseases which cell therapy can target are very varied: Hormonal dysfunction, such as diabetes and growth hormone deficiency; neurodegenerative diseases, such as Parkinson's, Alzheimer's and Huntington's; and cardiovascular lesions, such as myocardial infarction, peripheral vascular ischaemia; as well as lesions in the cornea, skeletal muscle, skin, joints and bones etc. The objective of cell therapy is to restore the lost function rather than produce a new organ, which could cause duplicity and undesirable effects. Several resources of cells can be used to restore the damaged tissue, such as resident stem cells, multipotent adult progenitor cells or embryonic stem cells. Some cell therapies have been established and approved for clinical use, such as artificial skin derived from keratinocytes, derived from chondrocyte, cells of the corneal limbus or pancreatic islet transplantation. These therapies have had good results, although the scarcity of the starting material may represent a serious limitation. Other therapies under research, using pluripotent stem cells, have been modest so it is useful to review the protocols and try to improve the outcomes. In this chapter we will review the new advances made in this way.