The Innovation platforms (IPs) approach was developed to address shortcomings of linear approaches to agricultural research and extension. However, `innovation platform' is a relatively new concept in agricultural research for development. There is limited knowledge and understanding of how best to organize IPs to facilitate numerous and multi-directional interaction among diverse stakeholders. The study examined how IPs are organized, the factors which motivated actors to participate in IPs, and the power dynamics within IPs. Data were collected from five IPs in Uganda and Rwanda Sept.-Dec. 2010. We conducted 184 semi-structured interviews with farmers, 34 in-depth interviews (with traders, extension workers, policy makers, NGO staff, researchers, IP chairpersons and non-IP members) and six focus group discussions with farmer representatives. I analyzed quantitative data using the Statistical Package for Social Scientists. Qualitative data were analyzed using line-by-line coding. The size of IP, age and nature of landscape influenced the extent of vertical and horizontal decentralization. IPs that were highly decentralized both vertically and horizontally demonstrated high knowledge and information sharing among actors. However, decentralization alone was not sufficient. Other factors need to be in place to facilitate interaction such as good leadership and proper infrastructure. Actors were motivated to participate in IPs by several factors (including development, material, economic, social and purposive). Farmers were primarily motivated by the desire to acquire knowledge and skills (developmental incentives). However, development incentives alone were not sufficient to encourage active farmer participation. Economic and material incentives encouraged farmers to continue participating. Participation of local policy makers and the private business sector was limited. Participation was curtailed by: expectation of tangible short-term benefits, poor understanding of IP concept, lack of resources, prior commitments and feeling devalued. IPs empowered farmers to prioritize issues of concern to them. However, concerns of small-scale local traders and women were not completely taken into account. Actors who accessed more information, knowledge, and financial resources demonstrated more power and influenced the decision-making, and implementation process. The key policy implications are to advocate for holistic, and integrative approaches that promote inclusion of the scientific and non-scientific communities in research. Government support is required for integrating IP activities in existing government programs and enforcement of bylaws.