AIM: The role of hepatitis B virus (HBV) genotypes on the clinical features and prognosis of patients with hepatocellular carcinoma (HCC) is currently unknown. The aim of the present study was to evaluate the distribution of HBV genotypes and their clinical relevance in Thai patients. METHODS: HBV genotypes were determined by PCR-RFLP in stored sera of 93 asymptomatic carriers, 103 patients with chronic hepatitis, 60 patients with cirrhosis and 76 patients with HCC. The clinical data were analyzed in relation to the HBV genotype. RESULTS: HBV genotypes C and B were predominant in Thailand, accounting for 73% and 21%, respectively. The distributions of genotypes B and C were similar in HCC patients compared to the other groups. Genotype C was significantly more common in HCC patients who were under 40 years old than genotype B (18% vs 0%, P= 0.03), but was significantly less common in patients older than 60 years (26% vs 56.5%, P= 0.01). The positive rate of hepatitis B e antigen (HBeAg) in patients with genotype C was significantly higher than that in patients with genotype B (71.6% vs 44.4%, P= 0.03 in chronic hepatitis; 56.8% vs 11.1%, P= 0.01 in cirrhosis). There were no differences between HCC patients with genotypes B and C regarding tumor staging by CLIP criteria and the overall median survival. Multivariate analyses showed that HBV genotype was not an independent prognostic factor of survival in HCC patients. CONCLUSION: Patients with genotype C had a higher positive rate of HBeAg and exhibited earlier progression of cirrhosis and HCC than those with genotype B. However, there were no differences in the risk of developing HCC and its prognosis between patients with these genotypes. AIM: The role of hepatitis B virus (HBV) genotypes on the clinical features and prognosis of patients with hepatocellular carcinoma (HCC) is currently unknown. The aim of the present study was to evaluate the distribution of HBV genotypes and their clinical relevance in Thai METHODS. HBV genotypes were determined by PCR-RFLP in stored sera of 93 asymptomatic carriers, 103 patients with chronic hepatitis, 60 patients with cirrhosis and 76 patients with HCC. The clinical data were analyzed in HBV to genotype. RESULTS: HBV genotype C and B were predominant in Thailand, accounting for 73% and 21% respectively. The distributions of genotypes B and C were similar in HCC patients compared to the other groups. Genotype C was significantly more common in HCC patients who were under 40 years old than genotype B (18% vs 0%, P = 0.03), but was significantly less common in patients older than 60 years (26% vs 56.5%, P = 0.01). The positive rate of hepatitis B e antigen ( HBeAg ) in patients with genotype C was significantly higher than that in patients with genotype B (71.6% vs 44.4%, P = 0.03 in chronic hepatitis; 56.8% vs 11.1%, P = 0.01 in cirrhosis). There were no differences between HCC patients with genotypes B and C regarding tumor staging by CLIP criteria and the overall median survival. Multivariate analyzes showed that HBV genotype was not an independent prognostic factor of survival in HCC patients. CONCLUSION: Patients with genotype C had a higher positive rate of HBeAg and exhibited earlier progression of cirrhosis and HCC than those with genotype B. However, there were no differences in the risk of developing HCC and its prognosis between patients with these genotypes.