This article explores the implementation of scalable agile frameworks in project portfolio management (PPM) of large companies when companies should approach an agile transformation process that works successfully in their PPM. This study adds to the limited knowledge on how companies find and manage the challenges they may be susceptible to during planning or anticipation of agile transformation. The qualitative case study method allows for the analysis of project portfolios with the implementation of scalable agile frameworks in large companies. Fifty-nine project portfolios from 22 companies were studied, and 43 semi-structured in-depth interviews were conducted. The results found portfolios of projects with high variability in service, product, and innovation and hybrid implementations of the Scaled Agile Framework (SAFe), Spotify Model, and Scrum, as well as different challenges related to the implementation of scalable agile frameworks in PPM, organizational culture, resistance to change, and strategic leadership. These findings show that agile frameworks are a viable option for achieving fast time-to-market, increasing team productivity, and improving overall communication. Given that the study addressed fifty-nine portfolios of projects in large companies, the analytical generalizations allowed us to find and verify theoretically significant patterns that can only be applied to this type of company and not to SMEs. Finally, the findings suggest the need for managerial development that promotes a broader orientation of scalable agile frameworks in PPM; specifically, better knowledge and skills about implementing these frameworks in companies to lead and organize an agile transformation successfully.INDEX TERMS Organizational agility, agile software development, agile project management, organizational transformation, project portfolio management, scaled agile framework (SAFe), project management.