In December 2016, the first bus rapid transit (BRT) service in Vietnam was introduced in an urban area of Hanoi, the capital, with a 14.7-km route. This study empirically investigates the impacts of introducing the Hanoi BRT service on the travel behaviors of commuters using public transportation services. A quasi-experimental approach is employed with difference-in-differences and propensity score matching to identify the impacts on commuters’ travel time, acceptable walking distance to the nearest stop, and modal share of public transportation. Interviews with public transportation users were conducted to collect data in June 2018, and 501 valid responses were obtained. Respondents were asked about their travel behaviors and perceptions regarding public transportation before and after the BRT introduction. The study assumes a treatment group containing commuters currently using the BRT service and a control group containing those currently using standard bus services. The estimation results reveal that the introduction of the Hanoi BRT service had significantly positive impacts on improving travel time efficiency, increasing the acceptable walking distance to the nearest stop, and encouraging commuters to use more public transportation in their daily journeys.