Diabetes is a chronic and progressive disease that affects an increasing number of patients. The prevalence of associated psychological comorbidities is high and often requires the implementation of targeted psychological interventions. Pancreas or islet transplantation remains a therapeutic option to consider, for a part of patients with type 1 diabetes unstable disease or established complications. From the clinical indication to the waiting period for a transplantation, then to the postoperative and long-term care, the diabetic patient is found to experience perpetual changes that may test his adaptability. In this article, the psychological aspects of the pancreas or islet transplantation, as well as the role of a liaison psychiatrist in a transplantation unit will be discussed.