The processing of agricultural product into quality forms not only prolongs the useful life of these products but also increases the net profit farmers make from such products. In this work, emphasis was place on demand led design which involved understanding the need of the farmer and designing an appropriate system that meets that need. The objectives of the work were to design, construct, and evaluate a low cost maize sheller for rural farmers in Nigeria. The methods used involved the collection of farmers opinion on their sheller needs, selecting appropriate materials, and utilization of theories of failure that enable the determination of allowable shear stress on the bearing supports. The communication methods used were an interactive sessions with farmers especially the women and children, in other to determine their shelling problems. Comparison was made between the human performance index for shelling and the machine performance index. The human mechanical efficiency, through-put capacity and grain handing capacity are 45%, 26.67kg/hr and 21.1kg/hr at a biomaterial test weight of 20kg with actual shelled weight of 15.8kg at a shelling time 45 minutes. For machine indices, through-put capacity and the grain handing capacity of the sheller are 86%, 119.76kg/hr and 109.99kg/hr respectively. The price difference shows a drastic reduction in the purchase price of maize thresher by N 32,500.00 ($216.67), which represent 56.52% price reduction. Market days were also used as an opportunity to show the farmers and agro-processors the advantage of using the maize sheller
