Farmer participation in decision making at various phases of project implementation contributes very highly to project success. The Soil-Water Management Research Programme (SWMRP) has gained valuable experience in the involvement of farmer in all phases during the implementation of the programme.  The programme used the following instruments to ensure farmer participation:  Socio-economic surveys including participatory and rapid rural appraisals, Farmer participation in on farm experimentation, Participatory technology evaluation through workshops and seminars aimed at monitoring project performance and getting feedback from stakeholders. The process of farmer participation evolved over the duration of the project. Lessons learnt at the beginning were incorporated in the research process over time. Initially, the planning of the experiments did not fully allow for farmer participation. This shortcoming was later rectified, and more farmer participation was allowed. Among the achievements of the project is the construction of a water diversion canal worth about Tanzanian Shillings 1.28 million in Hedaru village, Same District. The structure is currently supplying water to about 45 hectares in the village. The programme contributed only 18% of the total cost in terms of materials (6%) and technical support (12%). Farmer participation enabled mobilization of resources worth the remaining 82% of the total cost. The contributions were in the form of cash, labour, materials and decision making. This paper analyses the process of farmer participation in this programme and how it has influenced the performance of the programme. It is concluded that, with effective participation, minimum external support (small push) can result into substantial achievements.