The challenges inherent in leveraging the open innovation paradigm have created an opportunity for the emergence and increasing proliferation of open innovation intermediaries as actors supporting and facilitating this process. However, despite the growing emphasis on the importance of these intermediaries, the existing literature in this field has not adequately addressed the risks they face. Addressing this research gap, the present study aims to identify the risks that open innovation intermediaries encounter in the course of providing their services. To this end, an exploratory multiple case study design was employed, examining six open innovation intermediaries through in-depth, semi-structured interviews with senior practitioners and key informants embedded within them. Subsequently, the collected data were analyzed using thematic analysis, resulting in a comprehensive classification of risks encountered by these intermediaries, particularly across the sequential stages of a crowdsourcing-based intermediation project. This classification encompasses risks originating from the intermediation environment, collaboration formation with the client (seeker or problem/need owner), need/problem preparation, solution seeking (open call or broadcasting), participants, contributions (solutions, ideas, etc.), evaluation of contributions, the nature of intermediation, and the internal factors of the intermediary. Finally, the theoretical and professional implications of the research findings are discussed, and avenues for future research concerning intermediaries and the risks they face are also suggested.