We performed 6 islet transplantations in 4 type 1 diabetes mellitus patients. From September 2003 to April 2007, 23 islet isolations were performed from pancreata of non-heart-beating donors. The pancreata preserved using a 2-layer method or simple cold storage in University of Wisconsin solution were transferred to our cell processing center. The islet isolation was performed according to the Edmonton protocol with some modifications. The immunosuppressive protocol was achieved using sirolimus, tacrolimus, and anti-CD25 antibody (basiliximab). Islet yield was 400 to 491,040 IEQ and purity was 1% to 70%. Stimulation indices upon static incubation were 1.38 to 11.69. All patients who underwent islet transplantation showed positive serum C-peptide levels immediately after transplantation. Although insulin independence was not achieved, they displayed stabilized blood glucose levels, reduced insulin doses, and disappearance of hypoglycemic unawareness. Although stomatitis and diarrhea due to the side effects of sirolimus were observed in 2 patients, there were no severe complications. In patient 1, serum C-peptide levels decreased gradually from 1 year after transplantation. In conclusion, successful islet transplantation was possible using islets isolated from the pancreata of non-heart-beating donors. Further improvements are needed to achieve prolonged graft survival.