OBJECTIVE: Occult hepatitis B (OHB) virus infection is defined as the presence of hepatitis B virus (HBV) DNA in the liver tissue or serum of subjects seronegative for hepatitis B surface antigen. OHB leads to the potential risk of transmission in dialysis service. Routine HBV vaccine in dialysis patients is recommended. However, HBV vaccine response rates are lower than the community. The aim of this study was to determine the prevalence of OHB in hepatitis B vaccinated dialysis patients.