The treatment of patients with diabetes mellitus (DM) presents many challenges to care providers and represents a major proportion of healthcare expenditure worldwide. Successful pancreas transplantation provides durable glycemic control and improves survival for patients with diabetes. Progress in the field has mainly been based on large single center studies and the cumulative analyses of registry data from the United Network for Organ Sharing (UNOS) and the International Pancreas Transplant Registry. This review focuses on the outcomes of pancreas transplantation for patients with and without end stage renal disease. It describes the current state of pancreas transplantation, gaps in knowledge, and future studies needed to enable more patients to benefit from this treatment. A common theme that emerges is the need for multicenter randomized trials in pancreas transplantation to define clearly the efficacy, risks, and long term benefits.