The past few years have seen significant advancement in the clinical relevance of intraportal islet cell transplantation for treatment of type 1 diabetes mellitus. The implementation of novel protocols, such as the one developed by the group of Shapiro and collaborators in Edmonton, has revitalized the enthusiasm for cellular transplantation as a treatment for diabetes by improving the success rates and long-term function of islet grafts. Improved results in clinical islet transplantation reported by the groups in Edmonton, Miami, and Minneapolis have re-proposed the much simpler outpatient cell transplant procedure as an alternative to the more risky and technically challenging whole-organ pancreas transplantation.