Advisory services have long been considered key instruments to improve farm and crop management by introducing innovative practices and technologies in agricultural systems. Departing from a simple "technology transfer" perspective, participatory approaches were developed over the 1980s to enhance the design and adoption of innovations. Farmer field schools (FFS), an advisory service strongly based on participatory principles, aimed at supporting and fostering farmers' innovation. FFS have been used and adapted since the 1980s to meet context-specific needs in crop or farm management and foster integrative approaches. In this study, we report on interviews with some FFS project leaders and we assess the effective participation in a specific FFS experiment in central Tunisia. We show that, despite numerous studies reporting on FFS experiments, there are generally no available records on how participatory approaches were applied and on the extent of stakeholders' involvement. We contend that evaluating stakeholders' participation level via an assessment of the FFS application process becomes a must to improve their quality and effectiveness. Our results show that there is a gap in applying FFS operationally. Thus, planned activities will not be adapted to local scope specifications. Therefore, they are not easily adopted and are even more rejected by farmers. In conclusion, we suggest introducing new tools (e.g., role-playing games) to create an interactive environment for discussions between stakeholders and to enhance the capacity of local farmers to contribute to the design of FFS experiments according to their needs.