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 of firms 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.