Since 1982, the government of Korea has actively promoted vertical cooperative R&D programs between government‐sponsored research institutes (GRIs) and private firms. A number affirms participated in the programs because cooperative R&D could lower the risk and could contribute to rapid commercialization of many technologies. In this article, Chulwon Lee, Zong‐Tae Bae, and Jinjoo Lee examine the effectiveness of participant firms' strategies for commercial utilization of cooperative R&D results, from the viewpoint of technology sourcing at the project level. The data have been obtained from 162 cases of vertical cooperative R&D projects from a diverse group of industries in Korea. Three different commercialization strategies are empirically derived through cluster analysis of the relative usage rates of cooperative R&D and of other supplementary technology acquisition methods. They find that the effectiveness of these strategy clusters varies significantly according to the types of innovation, that is, project‐business relatedness. If the project belongs to an existing business area, in‐house development augmented cooperative R&D strategy is the most effective. On the other hand, licensing‐in supplemented cooperative R&D strategy is the most successful, if the project belongs to a new business area. Findings suggest that firms participating in cooperative R&D projects should try to utilize other supplementary technology acquisition methods in order to achieve commercial utilization of cooperative R&D results.