Hepatitis B virus (HBV) co-infection with human immunodeficiency virus is a major public health problem especially in developing countries. In this study, the prevalence of HBV infection was evaluated among 400 consenting HIV patients accessing healthcare in Federal Medical Center, Keffi, Nigeria using HBsAg detection as the surrogate. Blood samples were collected and screened for HBsAg using ACON screening kit (ACON Laboratories Inc, USA). The Chi-square statistical test was performed to identify possible determining factors associated with the viral infection. Overall, 30 (7.5%) of the participants were reactive to HBsAg. The possible determining factors for acquiring the virus recorded in this study were marital status and alcoholism (p0.05). This finding calls for a concern because co-infection of HBV with HIV accelerates disease progression and also has an effect on the management of patients infected with HIV.