The prevalence of hepatitis B virus (HBV) infection is reportedly high in Vietnamese Americans (VAs), but most previous studies did not assess full HBV serology, and not the prevalence of HBV and hepatitis C virus (HCV) infection simultaneously. The aim of the study is to assess the prevalence of different HBV serologies and HCV infection in VAs. This study was based on the data collected by testing for Hepatitis B surface antigen (HBsAg), anti-hepatitis B core antibody (HBcAb IgG), anti-HBs antibody (HBsAb), and anti-HCV antibody (anti-HCV) in a series of community screening in VAs in Orange County, California. In 1,405 VA participants, the mean age was 51 (17-87) years, 45.1% were males; 68.2%, married; 97.2%, born in Vietnam. Most of the participants were non-US born with their primary language being non-English and with limited access to health care. Of the 1,405 cases, 124 (8.8%) were confirmed HBV infection by HBsAg+; 81 (5.8%), HCV infection by anti-HCV+; including four (0.3%) with HBV/HCV coinfection. Twelve percent of the participants with confirmed HBV infection thought they were previously tested negative, while 29.7% of the participants with confirmed HCV infection thought they were previously tested negative. In this cohort, 15.4% were HBsAg-/HBsAb-/HBcAb IgG-, i.e. being susceptible to HBV infection. In HCV infected participants, 65.4% were born between 1945 and 1965. This large serial survey and screening in the Vietnamese American community confirmed the rates of HBV and HCV infection to be as high as 8.8% and 5.8%, respectively. We have also identified factors related to HBV and HCV infection in this high-risk population.