The PMO is a function responsible for creating a solid structure for the development of the organization. It is the main actor for the coordination and optimization of the activities related to a change management process. This study aimed to analyse the role of the PMO during a change management process, identifying the benefits and the difficulties encountered during the development of this project. The thesis starts with an overview of who is the PMO, which is its role and what are the main challenges that it will face; It will then go into the planning and organisation of a company, focusing on the importance of using project management techniques to efficiently develop a project.