Rice is a newly introduced crop to Ethiopia and the production is increasing every year, but little emphasis is given to postharvest handling practices. The current postharvest handling practices cause high losses. Threshing operation is mentioned as one of the major factors that influence postharvest losses. Hence, improving rice threshing practices through development, testing and promotion of mechanical thresher is imperative. In the present study threshing performances of a locally made thresher for different feed rates (FRs) (2000 kg/h, 3000 kg/h, 4000 kg/h) moisture content (MC) (12.4%, 17.3) and for three different local rice cultivars were conducted. The result showed that variety, feed rate (FR), and moisture content (MC) significantly affect threshing capacity, threshing efficiency, cleaning efficiency, and separation loss and grain damage. Higher threshing efficiency of 100% and threshing capacity of 1358 kg/h were recorded at lower MC and higher FR. Cleaning efficiency decreases with MC and FR. Higher cleaning efficiency of 92.5% was recorded at lower MC and FR. Separation loss increases with MC and FR. Higher separation loss of 5.4% was recorded at higher MC and FR. The result also showed a significant variation in grain damage with MC, a higher grain damage of 5.58% is recorded at lower MC and FR. Significant variations in specific energy requirements were also observed for the test conditions.