Hepatitis B infection is a global public health problem and is endemic in sub Saharan Africa. This disease has different modes of transmission and the infection is usually common in developing countries, including Nigeria. This study was carried out to determine the prevalence of HBsAg among patients attending Defence Headquarters Medical Centre, Asokoro, Abuja. The work was a random cross-sectional study that included 260 patients during the period of May to July 2020. A rapid diagnostic test kit was used for the screening for HBsAg. Out of the 260 patients tested, 10 were positive, giving a prevalence of 3.8%. The highest prevalence based on age was found among those aged 27 to 36 years with 2.28% seropositivity. The infection was highest among the low class of socioeconomic status with 5.21%. Patients who were not knowledgeable about the disease had a higher prevalence rate of 13.60% and lastly females had a higher prevalence rate of 4.55% compared to males (3.33). The prevalence of Hepatitis B infection is quite high in the studied population, which could have some public health implications. Recommendations have, therefore, been advanced to control and possibly eradicate the disease in no distant time.