The term “new onset diabetes after transplantation (NODAT)” refers to new incidence of diabetes mellitus after solid organ transplantation. NODAT is among the metabolic complications after liver transplantation that has been reported to be associated with negative impact on patient and graft survival. Several risk factors have been proposed but the precise pathogenesis has not been well demonstrated. It should be noted that not all patients, even with all of the risk factors, develop NODAT. This implies the role of genetic predisposition in the pathogenesis of NODAT.