ObjectiveThis study was performed in order to fill the gap of knowledge regarding sero-epidemiology of hepatitis B virus (HBV) amongst Human Immunodeficiency virus (HIV)-infected patients and to assess the risk factors associated with HBV co-infection in a rural locality of Cameroon. A retrospective and cross-sectional study was carried out from January 2008 to April 2014 within the Mfou District Hospital. Naive HIV-infected patients were enrolled in the study and tested for hepatitis B surface antigen (HBsAg). Preliminary pre-therapeutic data essential for follow-up was collected from the participants.ResultsOverall, the sample size was constituted of 712 HIV-infected patients. The prevalence of HBsAg was 8.99%. A significant difference was observed in the proportion of HBsAg positive subjects with respect to the year of inclusion; higher proportions were observed between 2011 and 2014 (P-value = 0.007). Majority of HBV co-infected participants had severe immuno-suppression with CD4 counts lower than 100 cells/µL as compared to HIV mono-infected population but the difference was not statistically significant. Our results confirm the high prevalence for HBV infection among HIV-infected patients in the Mfou District Hospital. These findings will enable stake holders to be better armed in the elimination of viral hepatitis as a public health problem.