Pancreas transplantation is the only treatment for type I diabetes mellitus that can induce an insulin-independent normoglycemic state. Because of the need for immunosuppression, it has been most widely applied in uremic diabetic recipients of kidney transplant with a high success rate, particularly when done as a simultaneous (SPK) procedure (insulin independence > 80% at 1 year) with patient and kidney graft survival rates equivalent to or higher than in those who receive a kidney transplant alone. The results of solitary pancreas transplants (PAK in nephropathic diabetic recipients or PTA in nonuremic recipients) have also dramatically improved; 1-year graft survival rates are more than 80% and 70%, respectively, with the new immunosuppressants tacrolimus and mycophenolate mofetil. Multiple factors are important for successful application of pancreas transplantation, as summarized in this review.