Understanding how scientific knowledge is transformed into commercial products in the market place and how to profit from technological innovations are important research issues. A key management challenge is how to transform promising technologies into economic returns by their commercialization. This study investigates the commercialization of government-sponsored firms and analyzes the relationship between their performance and determinants of the successful commercialization such as their internal and external capabilities. The empirical results show that the innovative capabilities, the investment on external R&D as the open innovation activities in the internal capability, and government funding for R&D and its commercialization in the external capability have significantly positive impacts on the commercialization. Moreover, it is found that the determinants of successful commercialization performance in the large-sized firm are different from those of the small- and medium-sized firm. This study is expected to contribute to the firms' formulation of their commercialization strategies to profit from their technological innovation and, in addition, the policy formulation to raise the firms' performance of technology commercialization.