infected individuals were included in this study. The HBV polymerase gene was analyzed by PCR and direct sequencing. HBV RT region mutations and amino acid changes were analyzed in BioEdit, by comparing the obtained sequences with a set of HBV reference sequences, HBV genotypes were determined using Geno2pheno HBV Database. Sixty- samples were successfully amplified by PCR. Our results showed low frequencies of classical primary drug resistance mutations (3%), (13%) of non-classical pre-treatment mutations, and a high frequency of nonclassical putative NA resistance mutations (65%). Among these, 56% were lamivudine resistance mutations, and 44% adefovir resistance mutations. A single primary resistance mutation to adefovir, „A194TÃ¢?? was detected in 2/60 CHB patients, two pretreatment mutations in 8/60 patients, and 11 putative resistance mutations in 39/60 patients. These results confirm that HBV mutations which confer resistance against currently available anti-HBV NA, may already exist in patients who have never received NA treatment.