Since the first report of successful pancreatic islet transplantation to reverse hyperglycaemia in diabetic rodents, there has been great interest in determining the optimal site for implantation. Although the portal vein remains the most frequently used site clinically, it is not ideal. About half of the islets introduced into the liver die during or shortly after transplantation. Although many patients achieve insulin independence after portal vein infusion of islets, in the long term most resume insulin injections.