This paper explores the decision-making processes of managing project portfolios in dynamic and uncertain environments. It focuses on how different managerial categories of project managers navigate unstructured situations and adapt their approaches to changing contexts. Capitalizing on this adaptability, the research reviews decision-making frameworks and uncertainty management practices to highlight strategies that enhance decision-making agility. Specifically, agile decision-making and iterative feedback loops emerge as pivotal mechanisms for effectively addressing uncertainty within portfolio management. The study thus stands to make a very significant theoretical contribution by basing its uncertainty management model on strategic portfolio governance and adaptive decision-making principles. Such a model will also lay the foundation for further empirical investigations and identify critical pathways for further research in the field. On a practical level, the research provides valuable managerial insights for organizations aiming to refine their decision-making processes, particularly in environments characterized by high levels of ambiguity. It underscores the importance of flexibility, responsiveness, and iterative learning in navigating complex and uncertain scenarios. It adds to the body of knowledge about uncertainty management in project portfolios through the advancement of theoretical understanding and actionable guidance. Portfolio managers can utilize these insights in navigating high-uncertainty environments, ensuring more resilient and adaptive portfolio management practices.