Over the years the Government of Tanzania has recognized the need for modern technology to increase agricultural production. Since the colonial period, agricultural research institutions have been established to cover most of the ecological zones of the country and research had been carried out on major crops by these institutes. However, recently critics have raised the question as to whether this research has been consistent with the needs of the majority of farmers. Closely related to this is the question of how effective the research findings have been communicated to the farmers. These questions have been raised due to the persistently low agricultural productivity and the use of traditional methods of farming, despite all the research that has been done in the country. This paper focuses on agricultural research in Tanzania. Its intention is to suggest ideas for further investigation into how to increase the effectiveness of the research system. This paper describes the evolution and major constraints faced in conducting agricultural research in Tanzania. The specific objectives of the study are to: 1) Identify the major constraints to agricultural research; 2) Examine the potential for the application of the Farming Systems Research approach; 3) Determine some of the analytical issues to be considered in agricultural research; and 4) Identify relevant analytical models to assess new technology for small farmers.