Background: Hepatitis C virus (HCV) causes significant morbidity and mortality worldwide. The infection induces up- regulation of cytokine and chemokine's commonly linked to the development of cellular and pro-inflammatory antiviral responses. The current standard in hepatitis C treatment consists of combination regimens of pegylated interferon-alpha plus ribavirin. Aim: This study was carried to follow up and monitoring the level of IL-17 in Hepatitis C infected patient before and after 120 days of treatment. Materials & Methods: Our study involved 120 HCV infected patients & 20 healthy persons; divided into three groups. Group I: IL-17 levels were measured in all subjects before and after 120 days of treatment. Also, Routine liver function tests were performed to all subjects included (aminotransferase (AST; alanine aminotransferase (ALT); Albumin; Total bilirubin; Direct Bilirubin, and alpha fetoprotein.  Results: our results demonstrated that; the level of IL-17 was increased in hepatic infected patients than the healthy group and also increased after 120 days of treatment, there is significance increased in other parameters as AST , ALT, AFP, while significance decrease in the level of Albumin. AUC (area under curve) value represents the combined effects of both sensitivity and specificity of Il-17 before and after treatments, as the sensitivity and specificity of it was 100% and 100%; respectively before treatment, was 70% and 100%; respectively after treatment. Conclusion: IL-17 was a sensitive & specific marker in the following-up and monitoring HCV patients treated with interferon and ribavirin.