Is it necessary or even possible to apply the management technology of open innovation to all projects in the same way? An analysis of the practices used in different product development projects in the same European medical company shows that commercially successful projects did apply many of the best practices for open innovation. However, projects were not equally successful. The outcome seems to be highly influenced by the type of collaborative arrangements used and their application. In particular, the analysis indicates that organizational factors seem to be indicative but not sufficient for success, and some open innovation practices were more successful than others. The most open and exploratory practices were not so successful in this company. This might be due to the nature of innovation, which develops in unpredictable and nonlinear ways. These observations suggest that those involved in open innovation need both a broad knowledge of the various potential elements of an open innovation effort and a flexible attitude toward their application. INSET: Summary of Projects.