Islet transplantation was first developed as an allogeneic procedure for patients with diabetes mellitus. When the initial allotransplants were unsuccessful, the procedure was attempted in a patient with chronic pancreatitis, undergoing total pancreatectomy using the patient’s own islets isolated from the diseased pancreas. The first patient to receive total pancreatectomy (TP) with islet autotransplantation (IAT), in 1977, was cured of a 20-year history of severe pain and remained insulin-free for 6 years until her death from an accident. Subsequently, TPIAT was adopted as a standard procedure for chronic pancreatitis by centers around the world. As of 2025, more than 2000 TPIAT procedures have been performed.