Islet transplantation, an innovative treatment strategy for type 1 diabetes mellitus, is a relatively safe procedure, with less morbidity than pancreas transplantation. Vascular injuries have not been reported to date. We report a percutaneous transhepatic intraportal islet transplant infusion that was followed by bleeding from a false aneurysm of an intrahepatic branch of the hepatic artery. The bleeding was controlled by selective embolization. Despite the complication and its treatment, the patient gained insulin independence, which was sustained for 285 days. She is currently on a small dose of insulin with good glycemic control.