Blood transfusion is a salutary practice in modern medicine, but it carries a high risk of transmission of transfusion transmitted infections (TTIs), especially in developing countries. The objective of this study is to determine the seroprevalence of viral hepatitis B among blood donors. This is a retrospective and descriptive cross-sectional study of the period from 2014 to 2016 at the Katele Health Reference Center (Moba, DR. Congo). We investigated HBsAg in blood donors by using Determine HBSAg. 1145 blood donors with an age mean of 30.6 ± 6.9 years and predominantly male (62.5%) were retained. The seroprevalence of hepatitis B infection from 2014 to 2016 was 3.9% (0.3% for 2014, 9.4% for 2015 and 0.7% for 2016). The family blood donors (83.2%) were the only carriers of HBsAg and were significantly associated with hepatitis B infection (p < 0.05). Age [OR = 0.70 CI 95% 0.34-1.44; p 0.338] and sex [OR = 0.72 95% CI 0.27-1.97; p 0.529] were not associated with the occurrence of hepatitis B in blood donors. The risk of transmission of HBV during transfusion remains high. We recommend the strengthening of transfusion safety measures, the abandonment of family donors for regular voluntary donors, the improvement of screening and diagnostic tests, the involvement of the national blood transfusion program in epidemiological surveillance and the mobilization of the population in favor of the fight against hepatitis B.