There is a small but growing literature on the staffs working in national parliaments. These are mostly single-country studies studying one role that staff can play or one principal that they serve. Our contribution provides a comprehensive measurement instrument of the role of parliamentary staff, which takes into account organisational diversity within and between parliaments. We recognise four types of staff that may be present to a greater or lesser extent in different parliaments, which have different principals (PPG staff, personal staff, plenary or committee staff). These different staffs can play different roles (information broker, advisor, ghostwriter, compromise facilitator and marketeer). We apply this typology to the Dutch lower house and find out how different types of staff combine multiple roles in practice.