This paper examines a novel project management methodology as a management innovation. Management innovations, like project management methodologies, are new practices introduced to organizations to further organizational goals and enhance their value. Although the topic of project management methodologies is widely covered in academia, little literature takes the perspective of management innovation or examines the potential barriers and drivers of the adoption of novel project management methodologies. In this study, we take a longitudinal and mixed methods approach as we investigate 17 Danish organizations and their adoption of a novel hybrid project management methodology innovation from initial adoption to a later stage of adoption. By drawing on management innovation, adoption, and diffusion literature, we identify drivers and barriers of adoption and diffusion centered around change agents and the notion of legitimacy. However, we also elaborate on the complexities of such a study and propose needed questions for future research. Contributions include a novel matrix to analyze adoption and diffusion as well as important implications for practice.