Islet of Langerhans transplantation is considered to be the ideal treatment for type I insulin-dependent diabetes. The permanent and adapted insulin secretion obtained by this method ensures prevention or even regression of the degenerative lesions which now constitute the severity of this frequent disease. Islets of Langerhans can be isolated from human pancreas and implanted freely in the liver or spleen. However, this source of grafts is limited and implantation of alloantigens requires the use of anti-rejection immunosuppressant therapy. The isolation of islets of Langerhans from porcine pancreas would represent an ideal solution to the shortage of human grafts, but the high immunoreactivity of xenoantigens prevents the possibility of free graft. For this reason, cell encapsulation systems in semipermeable and biocompatible membranes, at least theoretically able to ensure permanent tolerance of the cells, have been developed. The objective of this review is to inform general surgeons about the state of progress of studies in an area considered to be the first step of a promising therapeutic era in which they will be required to participate: that of cell therapy.