Background: Sudan is an endemic country for hepatitis B virus (HBV). Screening for HBV during pregnancy may help in instituting interventions to minimize vertical transmission. HBV in pregnant women in remote areas of Darfur were uncovered by the previous studies in Sudan, Objectives: This study was aimed to determine the seroprevalence of HBV and the possible risk factors for its acquisition among antenatal care attendants in Um Dafog area, South Darfur State, Sudan. Materials and Methods: A cross-sectional study was conducted between July, 2018 to January, 2019 in Um Dafog area. Blood samples were collected from165 (143from Sudan and 22from Central African Republic) pregnant women attending Antenatal Um Dafog Clinic. Serum was separated and tested for HBV marker using rapid HBsAg test. Information on socio-demographic and other pertinent data was collected using a structured questionnaire. Informed consent was obtained and confidentiality of personal data was assured.   Results: HBsAg was detected in 8.5% of study population. Participants from Central African Republic recorded higher prevalence (18.2%) than those from Sudan (7%). However, there was no significant association (P value > 0.05) between prevalence of HBsAg and residence, history of blood transfusion, tattooing, circumcision, surgical procedure, cupping therapy, caesarean section, ear piercing, unsafe injection, and jaundice or liver problems. Conclusion: The study concluded that the prevalence of HBV among pregnant women in Um Dafog area is of high endemicity according to WHO, hence the need for established public health interventions that leading  to reduction of HBV transmission. Keywords: Hepatitis B, pregnant women, Um Dafog, Sudan.