Background and study aim: Egypt unfortunately has the highest worldwide prevalence of chronic hepatitis C (CHC). Patients with CHC are advised to be vaccinated against hepatitis B virus (HBV) infection. Response to hepatitis B vaccination and risk factors for a weak response are not clearly defined. The aim of this study is to assess the response to hepatitis B vaccination in CHC patients and identify predictors of a weak response. Patients and Methods: This prospective study included 112 consecutive adult, treatment- naive, CHC patients (cases group) and 54 non-hepatitis C virus (HCV) subjects (control group). Demographic and laboratory variables including HCV-viral load, schistosomal antibody (Ab) titre, and histopathological examination of liver biopsy were assessed. Three intramuscular 20 µg doses (given at 0, 1 & 6 months) of HBV-vaccine (Euvax-B, Korea) were administered, and hepatitis B surface antibody (HBsAb) titres were evaluated 6-8 weeks after the 3rd dose. Results: Out of 112 CHC patients, five (4.5%) had HBsAb titres of