Background: CMV infection enhances HCV pathogenesis by preventing the normal mechanisms responsible for HCV clearance, thus playing vital role in HCV persistence and pathogenicity. Objective: To examine the effect of HCV - CMV coinfection on outcome of treatment with pegylated interferon alpha and Ribavirin in chronic HCV patients. Methodology: The study included of 50 cases selected from Outpatient Clinic of The National Hepatology and Tropical Medicine Research Institute (NHTMRI). Two groups were classified group 1 (positive HCV PCR and negative CMV Ig G) and included 15 patients versus group 2 (positive HCV PCR and positive CMV Ig G) and included 35 patients. Results: The non responders to treatment were higher in group 2 (65.7 %) than in group 1 (53.3 %) but with no statistical significance. Conclusion: CMV co-infection may influence the HCV treatment outcome, despite it failed to have statistical significance.