Background: Pregnant women infected with hepatitis B virus (HBV) can transmit the infection to their fetuses and newborns. Neonates who contract the HBV have about 90% risk of developing chronic HBsAg carriage (HBsAg: hepatitis B surface antigen) and chronic liver disease. Neonatal immunization interrupts this vertical and perinatal transmission. Objectives: To determine the seroprevalence of HBsAg among pregnant women attending the antenatal clinic at Aminu Kano Teaching Hospital (AKTH) and to identify potential risk factors associated with HBV infection. Materials and Methods: A case control study was conducted involving a total of 303 pregnant women attending the antenatal clinic at AKTH and 303 nonpregnant women of childbearing age. Blood sample was collected from each woman and the serum tested for the presence of HBsAg using latex rapid agglutination slide test kit (Cal-Tech Diagnostic Inc., USA) in the laboratory of the hospital. Reactive samples were stored at -20ºC and further confirmed for HBsAg using enzyme-linked immunosorbent assay (ELISA) kits (Bio-Rad, France). HBsAg-positive samples were tested for hepatitis B e antigen (HBeAg) using ELISA kits (Orgenics, Israel). A pretested, structured questionnaire was used for the collection of sociodemographic data and possible risk factors. Results: The prevalence of HBsAg among pregnant women and nonpregnant women were 7.9 and 7.6%, respectively. There was no statistically significant difference in the prevalence of HBsAg in pregnant and nonpregnant women. The presence of HBeAg was statistically significant among both pregnant and nonpregnant women who tested positive for HBsAg. The risk factors associated with HBV infection were blood transfusion, ear piercing, history of an affected sibling with HBV infection, tattooing, and abortion among pregnant women. Conclusion: The prevalence of HBsAg in this study was not statistically different in pregnant and nonpregnant women. There was a high level of HBeAg infection among pregnant women who tested positive for HBsAg. History of an affected sibling with HBV infection, tattoo, and abortion were significant risk factors for HBV infection.