Hepatitis B virus (HBV) was genotyped based on sequencing and analysis of nucleotide sequences of HBV S gene in sera samples from 176 patients with viral hepatitis B from all over the Czech Republic. The most frequent genotype A was detected in 118 (67.1%) of the patients, followed by genotype D found in 50 (28.4%) of the patients. Genotypes B and C were identified in 6 (3.4%) and 2 (1.1%) of the patients, respectively. The incidence of genotype A statistically significantly increases with age. There is no statistically significant correlation between genotypes A and D and gender or locality (region). Genotypes B and C, found mainly in South East Asia, were first detected in the Czech Republic. Detection of these genotypes in both foreigners and Czech population is suggestive not only of import but also of transmission of these genotypes in the Czech Republic. Fylogenetic analysis documents dissimilarity levels betweenHBVisolates. Based on theamino sequencederived, the percentages of HBV subtype determinants d (68.6%) and y (31.4%) were established. The gene S sequencing analysis proved suitable for HBV genotyping.

        Key words: hepatitis B virus – genotypes.