Hepatitis B virus (HBV) infection is a major health challenge in sub-Saharan Africa with a prevalence rate of >7%. It is an important clinical problem due to its potential adverse sequelae, including hepatocellular carcinoma. The additional challenge of its associated chronic infection makes its prevention difficult despite the widely available vaccine. Infectious chronic HBV carriers are likely to be the most common source of HBV infection in the community. This study aims to study the degree of infectiousness of HBV carriers by testing for HBV envelope antigen (HBeAg) and antibody among HBV carriers attending the gastrointestinal clinic at University College Hospital (UCH, Ibadan, Nigeria). This is a cross-sectional study among 129 consecutively recruited HBV infected individuals who gave informed consent to participate in the study. The participants of the study were recruited from clients attending the gastrointestinal clinic of UCH. The sera obtained from the participants were tested for HBsAg, HBeAg, and antibodies to HBV envelope antibodies (HBeAb) using commercially available enzyme-linked immunosorbent assay (ELISA) test kits by DIA.PRO (Diagnostic Bioprobes Srl, Milan, Italy) according to the manufacturer's instruction. Of 129 samples collected, 63 (48.8%) tested positive for HBeAg, whereas 72 (55.8%) tested positive for HBeAb (p = 0.012); HBeAg prevalence was higher in females than males and also prevalent among the age group of 31-40 years. Seventy-four (57.4%) of the participants also tested positive for both HBeAg and HBeAb, whereas 55 (42.6%) were negative for both. This study shows that there is a high level of infectiousness among HBsAg-positive individuals in Ibadan, Nigeria.