Due to its biological properties and the potential possibility of clinical application, the stem cells are currently the subject of an enormous interest. Totipotent stem cells isolated from the early embryo can develop into an embryo. Pluripotent stem cells from an organism selected mature differentiate into all tissue types that may soon find therapeutic use. It appears that the development of tissue engineering methods permit a tissue culture in vitro and their use in subsequent transplantation. The article discusses some of the recent developments concerning the isolation and culture of stem cells, with particular emphasis on stem cells present in cultures of human skin keratinocytes.