In this article, we assess the participatory experiences of a CIRAD research group created more than 20 years ago to provide support for a rural development plan for cattle farming in the highlands of Reunion Island. On the basis of an analysis of various Research & Development (R&D)projects, we evaluate the benefits and difficulties of a “Bottom-Up” approach. Four types of stakeholders have been systematically involved in these R&D projects. They all participate in the various steps of the innovation process. Although participatory approaches can be seen as timeconsuming and involving a risk of dispersion from the researcher’s point of view, they lead to radical changes in the respective roles of the various stakeholders involved,beneficial for both the effective production and dissemination of innovative measures.