Type I diabetes mellitus continues to be a serious disease with long-term morbidity from complications of the disease, despite better knowledge of physiology and better patient care. Pancreatic islet cell transplantation, still experimental, is gaining acceptance as a treatment strategy for individuals with type 1 diabetes who have poor glucose control and frequent hypoglycemic episodes despite maximal care. The procedure can improve glucose control, avoiding further hypoglycemic episodes, and can achieve insulin-independence at the expense of immunosuppression treatment. Islet cell transplantation does not correct all the metabolic abnormalities seen in type 1 diabetes, and glucose tolerance can remain abnormal. The dietary management of the patients still needs to be defined. Further research is focused at improvement in islet isolation and the refinement of immunosuppression strategies aiming toward immune tolerance, bringing hope for a cure of diabetes.