Background: Hepatitis C virus (HCV) is a major cause of chronic liver disease affecting close to 170 million people worldwide. Egypt Demographic Health Surveys (EDHS) measured antibody prevalence among adult population aged 15-59 years at 14.7% in 2009 and at 10.0% in 2015. Approximately, 85% of patients acutely infected with HCV progress to chronic liver disease with persistence of HCV RNA for more than 6 months. Among patients with chronic HCV infection, 15-20% progress to end-stage liver disease and approximately 14% of these patients progress to cirrhosis or hepatocellular carcinoma with time. With hepatitis C, being a national care problem, predicting the outcome of treatment in these patients becomes very important. Objectives: The aim of this study was to evaluate and predict the response in hepatitis C virus patients to pegylated interferon alpha and ribavirin therapy in association with estimation of the percentage of TH1 and TH17 by flowcytometry. Patients and Methods: This study was conducted on 50 patients with proven chronic hepatitis C virus infection based on by PCR technique and histopathology (25 responders and 25 non-responders). All of them were treated by combined pegylated interferon alfa plus ribavirin orally. Patients with history of previous interferon therapy, evidence of other systemic illness including: (hepatic, renal, cardiac, diabetic and neoplastic disease), chronic inflammatory disease, unstable thyroid dysfunction, unstable psychiatric disorder or history of any organ transplantation were excluded. All patients were F2or F3 on fibroscan. By flowcytometry, human CD4 percentage was estimated by using fluorescein-conjugated antibody. Human TH17 percentage was estimated by using PerCP-conjugated antibody, and TH1 was estimated by phycoerythron conjugated antibody. Both TH1 and TH17 were performed at weeks 0 and retested again after 12 weeks. Results: After 12 weeks from starting of therapy, there was an increase in percentage of TH1 in non-responders of therapy compared to responders with no difference in the percentage of TH17 between the two groups. Conclusion: There was a positive correlation between TH1 and TH17 in both groups before and after therapy. Also, we found that 98% of patients achieved sustained virological response 12 weeks after completion of therapy (SVR₁₂) showed sustained virological response 24 weeks after completion of therapy (SVR₂₄)_.