Cho Ray Blood Transfusion Center has been performing routine screening (Elisa, CMIA,...) to detect HBV, HCV, HIV, Syphilis,... At the same time, it also applies Nucleic Acid Technique (NAT) to early detection of viral genetic material and shortening the window period in infection with these viruses. Objective: To determine the prevalence of HBsAg, HCV antibodies, HIV, and syphilis in voluntary blood donors at Cho Ray Blood Transfusion Center in 5 years from 2017 to 2021.