Serum albumin has been reported to be a useful indicator of liver function and branched-chain amino acid (BCAA) therapy is associated with a lower incidence of hepatocellular carcinoma (HCC). We investigated the impact of BCAA granule therapy on overall survival and disease-specific survival in patients with normal albumin levels and low BCAA to tyrosine ratio (BTR)s who had treatment-naïve HCC. Overall survival and disease-specific survival was analyzed in 78 patients with HCC who were treated (n = 27) or not treated (n = 51) with BCAAs. Twenty-six patients died during the follow-up period. There were 19, 5, and 2 patients who died due to HCC, hepatic failure, and non-liver-related disease, respectively. Multivariate analysis for factors associated with overall survival indicated that BCAA therapy was independently associated with good prognosis in patients with HCC (hazard ratio [HR], 0.317; 95% confidence interval [CI], 0.123–0.813; P = 0.017). In addition, multivariate analysis using competing risks methods indicated that BCAA therapy is independently associated with reduction of disease-specific mortality (HR, 0.216; 95% CI, 0.068–0.689; P = 0.001). In conclusion, BCAA therapy improved both overall survival and disease-specific survival in HCC patients with low BTRs despite having normal albumin levels.