Aim. Our aim was to give a comparative assessment of the effectiveness of using narlaprevir in combination with pegylated interferon-alpha-2a (Peg-IFN-alpha-2a) and interferon-free mode in patients with chronic hepatitis C (CHC). Materials and methods. The prospective cohort study included 187 patients infected with genotype 1b of hepatitis C virus. Of these, 107 (the 1st group of patients) received narlaprevir 200 mg once a day, ritonavir 100 mg once a day, Peg-IFN-alpha-2a 180 mkg subcutaneously once a week and ribavirin at a dose depending on body weight (10001200 mg per day) for 12 weeks, and then the standart "dual" therapy (Peg-IFN-alpha-2a + ribavirin) was continued until 24 weeks. Patients of the 2nd group (n=80) received antiviral therapy in an interferon-free mode. They received narlaprevir 200 mg once daily, ritonavir 100 mg once daily, and daclatasvir 60 mg once daily for 12 weeks. Results. With the use of an interferon-containing treatment regimen, a sustained virological response was achieved in 92.4% of previousle untreated patients with CH and in 66.7% patients with "unsuccessful" experience of the previous course of treatment. In 5.6% of cases, there was an early termination of treatment due to the development of adverse events. 80 (100%) patients completed the course of treatment with narlaprevir in the interferon-free mode. Sustained virological response was reached by 75 (90%) patients. Conclusion. Real clinical practice indicates that the use of narlaprevir in the non-interferon mode is not inferior in efficiency to the interferon-containing treatment regimen and demonstrates a more favorable safety profile.