Abstract: Wheat and barley thresher was improved for its threshing capacity and suitability of operation and performance evaluation was done on wheat and barley crops. The size of previous wheat and barley thresher was increased and the feeding system that blows the dust outward to the operator was improved. The major components of the improved wheat and barley thresher include threshing unit, cleaning unit, feeding table, straw and chaff discharging unit and grain discharging unit. It was tested to thresh, separate and clean the wheat and barley seeds.