With the increased number of long-term survivors after liver transplantation, new-onset diabetes after transplantation (NODAT) is becoming more significant in patient follow-up. However, the incidence of new-onset diabetes after living-donor liver transplantation (LDLT) has not been well elucidated. The aim of this study was to evaluate the incidence and risk factors for NODAT in adult LDLT recipients at a single center in Japan. A retrospective study was performed on 161 adult patients without diabetes who had been followed up for threemonths after LDLT. NODAT was defined according to the 2003 American Diabetes Association/World Health Organization guidelines. The recipient-, donor-, operation-, and immunosuppression-associated risk factors for NODAT were assessed. Overall, the incidence of NODAT was 13.7% (22/161) with a mean follow-up of 49.8months. In a multivariate analysis, the identified risk factors for NODAT were donor liver-to-spleen (L-S) ratio (hazard ratio [HR]=0.022, 95% confidence interval [CI]=0.001-0.500, p=0.017), and steroid pulse therapy for acute rejection (HR=3.320, 95% CI=1.365-8.075, p=0.008). In conclusion, donor L-S ratio and steroid pulse therapy for acute rejection were independent predictors for NODAT in LDLT recipients. These findings can help in screening for NODAT and applying early interventions.