In the past, adult ABO incompatible living donor liver transplantation (ABO-I LDLT) had poor graft survival and low patient survival due to hyperacute rejection and a high risk of vascular biliary complication, and it was considered a contraindication. 1-4 Susceptibility to rejection, including severe hepatic necrosis and diffuse intravascular coagulation disorder within the graft, appears to be due to the blood group antigen expressed in the vascular endothelium and bile ducts after transplantation. 5,6 Various desensitization strategies have been introduced to overcome the barrier of ABO incompatibility. 7-9 However, desensitization protocols differ at each center, and the necessity of local infusion, splenectomy, intravenous immunoglobulin (IVIG), and plasmapheresis is controversial. After the rituximab era, the outcome of ABO-I LDLT has been reported in many studies to be comparable to ABO compatible living donor liver transplantation (ABO-C LDLT). 10-13 Many centers are now trying to simplify protocols. 14-20 We review the past and current immune strategies for desensitization and to provide outcomes and ABO incompatibility-related complications in ABO-I LDLT.