Normalization of serum alanine aminotransferase (ALT) levels is one of the goals of hepatitis B treatment. However, ALT levels in cirrhosis patients might be normal or mildly elevated regardless of ongoing inflammation. Therefore, we examined whether on-treatment ALT and other potential on-treatment indicators could be clinical surrogates of antiviral therapy in HBV-related cirrhosis. A total of 911 patients with HBV-related liver cirrhosis who started treatment with entecavir or tenofovir were analyzed. At 1 year of antiviral therapy, we evaluated ‘ALT normalization’, ‘undetectable serum HBV DNA’, ‘fibrosis-4 (FIB-4) index improvement’, and ‘serum HBeAg loss’ as potential biomarkers for HCC development. During 6.6 (3.8–10.2) years of follow-up, 222 patients (24.3%) newly developed HCC. Undetectable HBV DNA levels at 1 year were observed in 667 patients (73.2%), and the HCC incidence was significantly lower in this population (adjusted hazard ratio (HR) 0.66, 95% CI 0.50–0.87). Improvement of the FIB-4 index (< 3.25) was associated with a lower risk of HCC in 478 patients with an elevated FIB-4 index (adjusted HR 0.59, 95% CI 0.55–0.82). However, there was no significant difference in HCC risk between those with and without normalization of ALT levels (p= 0.39) among those with elevated ALT levels or between those with and without HBeAg seroconversion (p= 0.55) among HBeAg-positive patients. Therefore, on-treatment FIB-4 levels at 1 year are clinically useful surrogates of antiviral therapy for HBV-related cirrhosis patients.