Although research has been performed on participatory mechanisms in science and technology such as brokering, little seems written on intermediary organizations, e.g. science museums, taking up and embedding a participation brokerage role and systemic factors influencing these. This paper presents a qualitative case study in which six different intermediary organizations developed their participation brokerage role in a European RRI project. We demonstrate how structuring factors in the project context, the intermediary organization and the broader systemic context influenced the participation brokerage role take-up and embedding. Our findings yield implications for future capacity building endeavors among participation brokers in the making.