Inspired by innovation system theory, donors promote innovation platforms (IPs) to enhance collaboration for development. However, IP practice and impact are diverse: hence the question arises of whether and how IP approaches are able to create institutional change for the benefit of smallholders. The authors present the experience of an action research programme in West Africa and analyse the cases from a dialectic perspective on institutional entrepreneurship. The results show that a researcher-initiated open IP approach with clear principles and in-depth analysis of the value chain context is able to create reasonably effective IP coalitions for smallholder development. In a mature value chain, it may be possible to mobilize high-level actors, but IPs often start at a lower level and apply a two-pronged approach. They focus primarily on research and communication to improve smallholder technical and entrepreneurial practices, while diligently mobilizing high-level actors to attain critical regulatory and/or market support. Mobilization success is limited in contentious environments.