There are two types of indications for Langerhans islets transplantation, patients with type 1 diabetes mellitus who have a functional kidney graft but who cannot be candidates for total pancreas transplantation, and soon, patients without renal failure who develop particularly uncontrollable diabetes mellitus.Several conditions are required for the success of Langerhans islet transplantation: a laboratory with demonstrated skill is isolating islets, a sufficiently large number of islets for injection (600,000 for a 60-kg patient), fresh islets harvested within less than 24 hours before transplantation, effective immunosuppressive treatment with no toxic effect on Langerhans islets. The injection is a simple procedure performed under local anesthesia via transhepatic catheterization of the portal vein.Through 2000, 10% to 20% of implanted grafts were functional at 1 year. Islets survival has exceeded 80% at 1 year. The gold standard for success is withdrawal of insulin therapy and normal glucose control. Islets grafts will undoubtedly become the next important step in the treatment of type 1 diabetes mellitus, but other techniques are also envisaged for the future.