Objective: To determine the sero-prevalence and risk factors for Hepatitis B surface antigen (HBsAg) in sickle cell anaemia (SCA) patients in Nigeria. Design: Descriptive study method. Sera were screened for HBsAg, using the enzyme linked immune-absorbent assay (ELISA) kits. Personal information and risk factors associated with HBsAg were obtained, using a questionnaire. Setting: The Adult Haematology clinic, of the University of Benin Teaching Hospital, Benin City, Nigeria.Subjects: One hundred and fifteen HbSS patients aged 11-40 years. Results: The sero-prevalence of HBsAg was 20% in HbSS patients. The associated risk factors included socio-economic status class 7and 8, odds ratio 3.18,95% confidence interval (1.57-5.09) p