OBJECTIVE: The purpose of this study was to evaluate the relationship of IL28B rs12979860 and rs8099917 polymorphisms with the clinical, histological, and virological outcomes of patients with chronic hepatitis B (CHB) also the treatment responses of patients who received Nucleos(t)ide analogs (NAs) therapy.METHODS: This study included 152 CHB patients who were underwent liver parenchymal biopsy. The IL28B rs12979860 and rs8099917 polymorphism were genotyped using the TaqMan assay.RESULTS: The IL28B rs12979860 CC and IL28B rs8099917 TT were identified as the genotypes with the highest frequency in all patients. On the other hand, IL28B rs12979860 TT and IL28B rs8099917 GG were the genotypes with the lowest frequen-cy. The frequency of IL28B rs8099917 TG genotype was significantly different between patients with hepatitis B, who has his-tologically defined liver cirrhosis and no-fibrosis (p=0.02). In addition, a statistically significant correlation was found between the presence of IL28B rs8099917 G allele and virological unresponsiveness to NAs treatments in CHB patients (p=0.028).CONCLUSION: The presence of the IL28B rs8099917 G allele in CHB patients might be associated with the risk of develop-ing cirrhosis and virological unresponsiveness to NAs treatments.