Internationalization facilitates firms to achieve several potential benefits, however the internationalization process is accompanied by tremendous uncertainty and complexity on the firms’ operations. During past decades, several empirical findings show that there is no clear consensus about this relationship. Therefore, the objective of this paper is to estimate the effect of internationalization on firm performance of Vietnamese firms. The data collected from the listed firms’ annual reports on Hanoi stock exchange in the period of 2009 and 2018 are employed to test the proposed hypotheses. The OLS regression results reveal that the higher the degree of internationalization is, the higher their performance is. Furthermore, the empirical evidences also show that the performance of high internationalizing firms with high state ownership is higher than that of those with low state ownership. Whereas, the performance of high internationalizing firms governed by chief executive officer with the duality of the chairman of the boards is lower than that of those without duality. Building upon these results, some managerial implications are proposed in this paper.