Shadow rapporteurs play an important role in developing the European Parliament’s collective policy positions and in defending them in inter-institutional negotiations. This study sheds light on the ‘how’ and ‘why’ of shadow rapporteur selection. Qualitative insights from practitioner interviews and a quantitative analysis of shadow rapporteur data from the 7th European Parliament (2009–2014) indicate that the appointment process is primarily one of bottom-up self-selection by group members based on their policy interests. The party group leadership, in the form of group coordinators, plays an important coordinating role when there is competition for a shadow rapporteurship. However, the role of group coordinators is more akin to a third-party arbiter of competing demands than a mechanism of top-down control by the leadership, as suggested by principal-agent theory.