Recognition that conventional research processes and the quantum leaps in food grain yields generated by the "Green Revolution" in the 1970s were not reaching the majority of the world's small farmers gave rise to an interest in the potential contributions of farmer knowledge to agricultural development. A growing understanding of small farmers and the circumstances under which they operate led to the emergence of an evolving farmer-oriented approach to technology development. In an effort to reduce the increasing gap between on-station and on-farm performance, researchers began to look for ways to identify key aspects of farmer wisdom and experience and to incorporate this body of knowledge into the agricultural technology development process. This paper provides a brief overview of the various processes and methods that have been used to achieve this integration and their relative success. Scientific and local knowledge systems are compared and contrasted in terms of their defining characteristics. An assessment is made of the varying impacts of farmer knowledge within the agricultural research and extension process and comments are offered concerning the need for continued change in the roles of researchers and farmers to achieve a more integrated and balanced role for farmers in agricultural technology development.