Albumin-bilirubin (ALBI) grade is an index of liver function based on total bilirubin (T-BIL) and albumin levels, and its usefulness has been widely reported. This study aimed to investigate the effect of different methods of measuring T-BIL and albumin levels on the ALBI grade in patients with liver disease. In total, 170 patients from our hospital were included in this study. Correlations between T-BIL levels measured using the vanadate oxidation and enzymatic methods were analysed. Similarly, a correlation analysis of albumin levels between the bromocresol green (BCG) and modified bromocresol purple (BCP) methods was performed. Additionally, the ALBI grade was calculated for patients with liver disease, and the differences between each method of albumin measurement were compared. No differences were observed in the measured T-BIL values between the two methods. Contrastingly, the albumin levels of 100 random samples and 70 liver disease patients obtained using the modified BCP method were significantly lower than those measured using the BCG method. The rate of change in the modified ALBI grade between the BCG and BCP methods was 25.7%. Caution should be taken when comparing ALBI grades with those measured by other facilities because the method of albumin measurement can affect the ALBI grade. Standardization of albumin measurement is needed worldwide.