For decades a structured development process was followed when developing software. However, the suggested predictability of such an approach has long been proofed erroneous and in its place, more flexible methods have been suggested. Such agile methods are less structured and trust in the creativity of the development team in countering unpredicted events and realizing a solution. Currently one of the most popular agile methodologies is Scrum. There are only three roles in Scrum: the development team, the Scrum master and the product owner. As the product owner is responsible for maximizing the value of the product and the work of the development team, this role is key in the success of Scrum. However, the competences needed by the product owner are unclear. Based on this the research question underlying this study is: Which competences of the Scrum product owner are related to team effectiveness and stakeholder satisfaction? In order to answer this question empirical data was collected from 141 employees in organizations in the Netherlands. To analyse the data, we have conducted correlation analyses, t-tests and regression analyses. The most important findings are that the competences ‘Relationship management’ and ‘User support’ are the main predictor for both Team effectiveness as Stakeholder satisfaction.