For several years, in Parkinson's disease patients, immature neuroblasts grafts could be realized. Those immature cells come from mesencephalic regions of six to ten weeks-old embryos. Given several technical problems, clinical outcome of the patients is not favourable and moreover, it appears that the cell source is very limited. That's the reason why the use of embryonic or somatic stem cells could be promising. Stem cells are able to self-renew, and could differentiate into several cell types. In this lecture, the author reviews the biological properties of different stem cells types in order to be used in cerebral graft in several neurological diseases. Given their recently unravelled phenotypic plasticity, somatic stem cells could be the best candidate for such a clinical use for autografts.