Background: The albumin-bilirubin (ALBI) score is a simple and objective indicator for liver function, but its role and clinical significance in liver transplantation (LTx) are unclear. The study aimed to investigate its utility as a predictor of short- and longterm outcomes in LTx recipients. Methods: The study included 351 consecutive LTx recipients (217 adults, 134 pediatric) who underwent their first LTx between 1990 and 2022. Study 1: patients were classified into low-ALBI (grade 1 or 2) and high-ALBI (grade 3) groups based on ALBI score at LTx. Background factors and short-term outcomes were compared. ALBI scores utility as a predictor for long-term prognosis was evaluated by ROC and multivariate analysis. Study 2: we examined the changes in ALBI score post-LTx and its usefulness as a follow-up marker. Results: In Study 1, ALBI scores at LTx were: adults (–1.63±0.77), pediatric (–1.25±0.59). High-ALBI group had more severe liver failure (model for end-stage liver disease [MELD], 21 vs. 12; pediatric end-stage liver disease [PELD], 19 vs. 12) and massive blood loss. No significant increase in complications, but the high-ALBI group had three times higher in-hospital mortality (13% vs. 4%, P=0.020). In the adult cohort, the ALBI score was better than MELD/ChildPugh scores in graft failure prediction. Graft survival was significantly worse in the high-ALBI and was identified as an independent prognostic factor (hazard ratio, 3.23; 95% confidence interval, 1.80–5.82; P<0.001). In Study 2, ALBI scores improved at 1-year post-LTx for adults (–2.67) and pedi-atric cases (–2.77), stabilizing over 20 years. Receiver operating characteristic analysis revealed ALBI score at 1 year predicted graft failure (area under the curve: adults 0.83, pediatric 0.85, P<0.001), and ALBI grade 2 linked to poor graft survival. Conclusions: High ALBI at LTx predicted poor outcomes in adults. Subsequent ALBI increases post-LTx correlated with poor graft prognosis in both adult and pediatric cases, indicating the importance of investigation and intervention, including retransplantation considerations.