This paper analyses the organizational, financial and technological incentives that service organizations used to motivate farmers to finance agricultural research and extension in Benin. Understanding the foundations and implications of these motivation systems is important for improving farmer financial participation in agricultural research and extension. We studied three cases of farmer financial participation in the field of agricultural research and extension in Benin. We conducted semi-structured interviews with leaders of service organizations and farmers' associations, local authorities and individual farmers. Our interviews focused on service delivery systems, mechanisms of farmers' financial contribution, the functioning of farmers' associations, and the appropriateness of services provided. We performed thematic and comparative analyses at the interfaces between (1) service providers and partner-farmer associations, (2) service providers and delivered services, and (3) farmers/farmers' associations and services. Incentives for farmer financial participation are the increasing participation strategy, the fulfillment of farmers' needs and the local leadership valorization. The selection and combination of their variants determine the motivating capacity and orientation of service organizations. Conversely to the increasing participation strategy, an effective fulfillment of farmers' needs and local leadership valorization can lead to sustainable motivation. As the fulfillment of farmers' needs determines importantly the effectiveness and sustainability of farmers' motivation, the strategies of farmer financial participation are likely to fail if there are no successful agricultural technological incentives. In the current context of privatization of agricultural services in developing countries, this analytical framework is of interest for policy makers and development workers for identifying conditions of farmer financial participation and designing effective motivation strategies. (Contains 5 tables and 2 figures.)