To master tissue and organ morphogenesis necessitates a thorough understanding of the cellular and molecular events involved in development, renewal, repair and regeneration. Skin reconstruction is the paradigm of tissue engineering. The transplantation of autologous adult epidermal stem cells is a life-saving procedure as it regenerates the indispensable barrier function of the skin, but the reconstruction of fully functional skin has been hampered by the complexity of the process. The recent identification of multipotent epithelial stem cells in adult hair follicles and of multipotent stem cells in dermis raises new hopes.