Objective: Increasing evidences suggest that oxidative stress is closely related to the pathogenesis of hepatitis C virus (HCV) infection. The purpose of this study was to examine the dynamic thiol/disulfide homeostasis (DTDH) and total oxidant/antioxidant status in patients with HCV infection. Methods: Levels of serum total thiol (TT), native thiol (NT), disulfide (DS), total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI; TOS/TAS ratio) as oxidative stress markers were determined in 162 individuals, including 74 patients with HCV infection and 88 non-HCV controls. Results: The NT, TT levels and NT/TT ratio were significantly lower and DS level, DS/NT and DS/TT ratios were significantly higher in HCV group compared to the control group. The TOS and OSI values were significantly higher and the TAS level was significantly lower in the HCV group than in the control group. No significant correlations were found between oxidative stress markers and albumin, alanine aminotransferase, aspartate aminotransferase and bilirubin levels in patients with HCV infection. A negative correlation was found only between OSI and albumin. Conclusion: These results indicate that patients with HCV infection are vulnerable to oxidative stress and have disturbed status of oxidant and antioxidant.