BACKGROUND The role of nutritional parameter prealbumin in predicting the incidence of hepatic encephalopathy (HE) remains unclear. This study was designed to assess the diagnostic performance of prealbumin in predicting the incidence of HE in hepatitis B virus (HBV)-related decompensated liver cirrhosis patients. MATERIAL AND METHODS A retrospective cohort of 262 patients with HBV-related decompensated liver cirrhosis was involved in this study. Prealbumin, albumin, and other indicators were collected at admission, and independent factors were identified by logistic regression analysis. The Mann-Whitney U test and receiver operating characteristic (ROC) curves were used to compare the groups and indicators. RESULTS A total of 262 patients were enrolled in the study, including 197 men and 65 women. In patients with HBV-related decompensated liver cirrhosis accompanied by HE, the model for end-stage liver disease (MELD) scores, and prothrombin time (PT) and international normalized ratio (INR) values were significantly increased, while prealbumin and albumin levels were significantly decreased. Multivariate analysis showed that only serum prealbumin level (P=0.014) was independently related to the incidence of HE. Moreover, prealbumin level was negatively correlated with MELD (r=-0.63, P<0.001) and Child-Turcotte-Pugh (r=-0.35, P<0.001) scores. ROC curves were performed, and prealbumin showed the highest area under the ROC curve (0.781) compared with MELD and Child-Turcotte-Pugh scores. CONCLUSIONS Low prealbumin levels were associated with increased frequency of hepatic encephalopathy in HBV-related decompensated cirrhosis, which showed better performance than traditional models.