Type 1 diabetes currently affects 15,000 patients in Switzerland with a rising incidence worldwide. Pancreas or islet of Langerhans transplantation are alternatives to intensive insulin treatment, which decreases long-term complications at the cost of an increase of severe hyoglycemia. Pancreas transplantation, indicated mainly to diabetic patients with simultaneous kidney transplantation, has a high success rate, but is accompanied by high morbidity due to general surgery. Islet transplantation, a cell-therapy for type 1 diabetes, is in full development. It is mainly indicated as islet transplant alone in patients suffering from brittle diabetes, and is associated with a very low risk due to minimally invasive technique, but a lower rate of long-term success. New potential sources of beta cell replacement are beta-cell lines, stem cells and xenotransplantation.