BackgroundIn Gabon, data on hepatitis B virus (HBV) infection are limited to HBs Ag detection among specific populations and rural regions. Thus, this is the first study aimed at determining the seroprevalence of HBV markers among the Gabonese population. MethodsA retrospective study was conducted from January 2002 through December 2022. All patients who requested HBV marker screening (HBsAg, Ab anti-HBc, Ab anti-HBs, Ab anti-HBe, HBeAg) were included in this study. ResultsFour hundred nineteen-six (496) people were included in this study. The prevalence of HBV exposure was high (59.5%) and significantly associated with age, sex, pregnancy status and social status. Among those individuals with evidence of HBV exposure, only 89 (33.7%) had effectively cleared the virus. Overall, HBsAg was detected in 108 of the 496 (21.8%) people included in the study. HBsAg infection was more common among individuals in the 16-25 (35.1%) and 26-35 years (30.6%) age groups. Moreover, the majority of HBsAg-infected patients were HCWs (p=0.0096). Among the 496 individuals included in this study, 126 (25.4%) were still susceptible to HBV. Most of the susceptible females were pregnant (p < 0.0001). Workers who were HCWs had a significantly lower probability of being naïve to HBV infection (p=0.0001). There was a similar prevalence of susceptibility in males and females (50 (24.5%) males and 76 (26.0%) females). Only 15.1% of the studied population was vaccinated. ConclusionOur findings revealed a high seroprevalence of HBV infection in the study area and very low HBV immunization coverage. Extra care and resources should be provided to promote HBV vaccination and block vertical HBV transmission.