['The recurrence rate of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is high even in patients receiving curative therapy. In this study, we analysed the risk factors for tumour recurrence after curative therapy for HBV-related HCC while under treatment with nucleot(s)ide analogues (NAs) by measuring serum HBcrAg and intrahepatic covalently closed circular DNA (cccDNA) levels to elucidate the viral status associated with HCC recurrence.', 'We enrolled 55 patients who developed HCC during NA therapy and underwent either curative resection or percutaneous ablation for HCC.', 'Hepatocellular carcinoma recurred in 21 (38%) of the patients over a period of 2.2 (range, 0.2-7.4) years. In multivariate analysis, serum HBcrAg levels ≥4.8 log U/ml at the time of HCC diagnosis (hazard ratio, 8.96; 95% confidential interval, 1.94-41.4) and portal vein invasion (3.94, 1.25-12.4) were independent factors for HCC recurrence. The recurrence-free survival rates of the high cccDNA group were significantly lower than those of the low cccDNA group only in patients who underwent resection (P=0.0438). A positive correlation (P=0.028; r=0.479) was observed between the intrahepatic cccDNA and the serum HBcrAg levels at the incidence of HCC.'] Is hBcrAg a predictor of post-treatment recurrence of hepatocellular carcinoma during antiviral therapy?