Background: In Nigeria, hepatitis co-infection with HIV is linked with an increase in morbidity and mortality. Objective: The goal of this study was to investigate the rate of HIV/HBV coinfection among the highly HIV-infected people in Rivers State, Nigeria. Study Design: Cross-sectional study. Place and Duration of Study: University of Port Harcourt Teaching Hospital (UPTH), in Rivers State, Nigeria, from February 2017 to September 2019. Methods: A total of 226 HIV-positive people, 105 men and 121 women, were recruited for this study. ELISA was used to screen these participants for the presence of HIV and HBsAg, and this was done following the guidelines stipulated by the manufacturer. The demographic characteristics of the participants were obtained using a questionnaire designed for the study. Results: Seven people tested positive for HIV/HBV, resulting in a 3.1 % overall prevalence. No significant association was found to exist between HIV/HBV coinfection and the characteristics of the study population. Conclusion: A low seroprevalence was observed for HIV/HBV infection, in spite of Nigeria being endemic for HBV. Despite this low rate of HIV/HBV coinfection, routine screening for HBV markers should be carried out to reduce morbidity and mortality in this group.