Pancreas transplantation is the only treatment presently available for patients with Type 1 diabetes that establishes both insulin independence and sustained normoglycaemia. This normoglycaemia is associated with potential beneficial effects on the secondary microvascular complications of diabetes. Pancreas transplantation also improves the quality of life for diabetic patients. Islet transplantation has had only limited success to date, but when successful restores regulated insulin secretion and establishes insulin independence. However, despite the benefits of both pancreas and islet transplant for carbohydrate metabolism and diabetic complications, neither is considered standard therapy for patients with IDDM. Both types of transplantation require life-long immunosuppressive therapy. Pancreas transplant is further limited by the significant risks of the surgical procedure. In order for either pancreas or islet transplantation to achieve the clinical acceptability of other forms of transplantation, clear advantages over exogenous insulin therapy must be demonstrated.