Aim. The aim of this study was to characterize the genetic profile of patients with chronic hepatitis C virus (HCV) infection relative to polymorphisms rs12979860 and rs8099917 in gene IL28B and the association of those polymorphisms with the response to treatment with pegylated interferon and ribavirin, performed at a reference center in Brazilian Amazonia. Methods. A total of 75 individuals with chronic hepatitis C and 98 healthy individuals from both genders over 18 years old were assessed. DNA samples were collected from leukocytes and subjected to real-time polymerase chain reaction to genotype polymorphisms rs12979860 and rs8099917. Results. Analysis of the allelic and genotypic frequencies of the investigated polymorphisms showed that both groups were in Hardy-Weinberg equilibrium; polymorphism rs12979860 exhibited no significant difference between the groups. For polymorphism rs8099917, allele T was significantly less frequent ( P = 0.0195) among the patients (63.3%) than the controls (75.5%), and the patients were 1.7 times as likely to exhibit allele G. No difference in response to treatment was associated with SNP patterns. Conclusion. The results suggest a possible association of SNP rs8099917 with higher odds of chronic HCV infection but do not indicate a putative influence of the investigated SNPs on the sustained virologic response.