Objective: This study aimed to determine sensitivity, specificity, and accuracy of RDT used in 4 health care centres in Vientiane capital versus ELISA. Methods: A study was then conducted among 1,729 patients who underwent three different RDTs for surface antigen of hepatitis virus (Boson, CTK and Coretest) in two public central hospitals and two private clinics in Vientiane Capital, to compare sensitivity, specificity, and accuracy of RDTs versus ELISA. Results: The mean age (95%CI) of the patients was 28.7 years old and the sex ratio was balanced. 13.71% of the patients had positive HBsAg as detected by ELISA, while this was only 8.9% for RDTs. All three types of RDTs had a sensitivity of 54% and specificity of 97%. There was no difference in accuracy, sensitivity, specificity, positive and negative predictive values between RDTs. Conclusions This study revealed higher prevalence of HBsAg among young adults who were present in health care facilities in Vientiane than previously described in Laos. All three RDTs studied had low sensitivity but high specificity; therefore, they are likely to miss many cases of Hepatitis B infection and should be replaced or backed up by more accurate methods.