The albumin-bilirubin (ALBI) score is a new model for assessing the severity of liver dysfunction. The purpose of the present study is to investigate the prognostic value of the ALBI score in predicting the 3-month outcome of patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (AoCLF).This study included 84 patients with HBV-AoCLF, 56 chronic hepatitis B (CHB) patients, and 48 healthy controls (HCs). The virological parameters and biochemical examination of blood were obtained after 12 hours of fasting. The follow-up of AoCLF patients lasted for at least 3 months, and the relationships between the prognosis and ALBI score were analyzed.A significantly higher ALBI score was detected in AoCLF patients than in the HC and CHB groups (both P = .001). The ALBI score was positively correlated with the model of the end-stage liver disease (MELD) score and Child-Pugh score. Moreover, ALBI scores were higher among non-survivors than survivors in AoCLF patients. Multivariate analysis suggested that both the ALBI and MELD scores were independent predictors of the 3-month mortality in AoCLF patients (P < .001).A high ALBI score measured at admission may be used as a predictor for the 3-month mortality rate in patients with HBV-AoCLF.