This research determines the impact of foreign direct investment (FDI) on the economic growth of Vietnam (economic) over the period 1990 to 2020after the political and economic reforms (Doi Moi) in 1986. The study uses the VAR model through unit root test, Granger causality, impulse response,and variance decompositions to achieve the goal of finding the impacts of FDI on economic growth. The study finds that the impact of FDI on economicgrowth in the short-term and harms the growth for the long-term. Despite the increase of FDI capital over the years and its potential, the effectiveness ofFDI is still limited. In this context, this study is written in parallel to provide a systematic study on the determinants of FDI and its potential impacts on theeconomy of Vietnam.