Pancreas or islet transplantation is the most physiologic approach to cure diabetes mellitus. Advantages of islet transplantation are less invasive procedure, easy access to immunomanipulation, and possibility of retransplantation. However, there are several obstacles to achieve successful islet transplantation: insufficient number and and toxic effect of islets, of current nonspecific inflammatory reaction and immune injuries, immunosuppressive drugs. A method to improve the yield of islet mass is briefly discussed. Methods to prevent nonspecific inflammatory reaction and immunoisolation such as rechargeable islet device to protect the immune attack are then described. Finally, future aspects on the field of islet transplantation are provided.