Background: chronic hepatitis C virus (HCV) is a major cause of liver-related morbidity and mortality. Successful antiviral therapy with sustained viral clearance is associated with improved quality of life, and reduced risk of liver complications such as cirrhosis and hepatocellular carcinoma. Aim of the Work: to evaluate the impact of HCV eradication using direct acting antiviral drugs (DAADs) on cognitive function among hepatitis c virus infected patients. Patients and Methods: this study was conducted at Viral Hepatitis Unit of Dar El Shefaa Hospital (one of the centers of national committee for control of viral hepatitis) and MASRI (Faculty of Medicine Ain-Shams Research institute) unit at El-Demerdash Hospital. Data were prospectively collected using MoCA, PHQ-9 and PSQI scales to assess the cognitive function of the treated patients with the newly used DAADs before the start of treatment, during treatment and at 12 weeks after the end of treatment, and the laboratory data were collected from the files of the patients in the previously mentioned centers. Results: results of the current study as regarding the analytical part of the study showed that: Pre treatment: slightly cognitive impairment was found with mild level of depression and sleep disturbance with MoCA test Mean ± SD 23.02 ± 4.96. At the end of treatment: there was no direct effect of the newly used drugs on the cognitive function. After 3 months of treatment (SVR): there was significant improvement of the cognitive function. Conclusion: HCV eradication had beneficial effect on cognitive function. Sofosbuvir based treatment had no effect on cognitive function.