BACKGROUNG: Epstein-Barr virus (EBV) infection represents ubiquitous etiology that can exert hepatic manifestations. The role of EBV in worsening liver fibrosis among chronic hepatitis C virus (HCV) infected patients is not well defined. The fibrosis index based on 4 factors (FIB-4) is used as a crucial non-invasive biomarker to diagnose liver fibrosis in chronic HCV infection. OBJECTIVE: This study aimed to investigate EBV seroprevalence in chronic HCV patients through the assessment of the corresponding antibodies, referring to their relationship with FIB4 score-based liver fibrosis. METHODS: A total of 141 participants were involved in this study (81 chronic HCV patients and 60 controls). All participants were subjected to the measurements of baseline clinical parameters including HCV RNA. The FIB4 score was calculated to determine liver fibrosis. Serum samples were investigated for EBV-VCA IgG and EBV-VCA IgM antibodies by ELISA. RESULTS: EBV-VCA IgG antibodies exhibited 100% seropositivity in chronic HCV patients and controls, whereas the seropositivity of EBV-VCA IgM antibodies was detected in 6/81 (7.704%,) of chronic HCV patients (HCV/EBV co-infection) compared with 0/60 (0%) in controls. A significant increase in the seroprevalence of EBV-VCA IgM antibodies was observed in chronic HCV patients compared with controls (P 0.038). A significant increase in the total bilirubin level was reported among HCV/EBV co-infected patients compared with HCV mono-infected others (P < 0.001). At the FIB4 score high cutoff value of 3.25, a non-significant difference in EBV-VCA IgM antibody seropositivity between chronic HCV patients having significant (late) fibrosis (≥ F2, n = 60) and those having non-significant (early) fibrosis (< F2, n = 21) was reported, and no association between HCV/EBV co-infection and liver fibrosis was found. However, the incidence of increased EBV-VCA IgG antibody titre was found to be associated with chronic HCV patients having late fibrosis compared to those having early fibrosis (Odd's ratio 28.863, 95% C.I. 1.6691 to 499.1025, and P 0.020). Additionally, at the FIB4 score low cutoff value of 1.45, there was no significant association between seroprevalence of EBV-VCA IgM antibodies or incidence of increased EBV-VCA IgG antibody titre and a high probability of ruling out late fibrosis in chronic HCV patients.  CONCLUSION: Chronic HCV patients predominantly have EBV-VCA IgG antibodies; the incidence of increased titre of these antibodies is associated with liver fibrosis progression. However, EBV reactivation is indicated by increased seroprevalence of EBV-VCA IgM antibodies, which does not show any association with liver fibrosis progression in the studied cohort of HCV patients.