The Farmer Field School (FFS) originated in the 1980s in the context of integrated pest management in Indonesian rice farming. With the hope that it is the remedy for agricultural extension system, FFS has been promoted as a tool for participatory learning and experimentation all over the world. This work results from a critical analysis of the introduction of the FFS concept into the agricultural innovation system in Uganda. Ideally, an FFS produces new technical knowledge in the context of application through the input of local human resources. The analysis, framed as a technography, shows that implementation and operation of an FFS is hugely complex. This detailed study of institutional factors, from the level of international donor organizations down to the level of local leadership and gender relations, and analysis of technical factors in different rural areas of Uganda makes clear that and FFS is more than a local tool for farmer participation in agricultural improvement. Implementation of a FFS requires adjustment of the agricultural innovation system at all levels and an integrated tackling of agricultural problems in order to meet its objectives. Isubikalu shows that it is imperative to 'demolish' existing organizational structures and create new ones, which align scientific with local structures to produce an appropriate people-centered system that is more responsive to agricultural and rural development. She provides stepping stones in redesigning FFS to fit the specific conditions in Uganda.