Experiments were conducted to evaluate the performance of a locally machine for sifiting and cleaning some agricultural crop grains. The performance of the sifting and cleaning machine was experimentally measured under the following parameters: two different types of crop grains: rice and wheat; four different feed rates of about 0.135, 0.155, 0.180 and 0.24 Mg/h: three different grain moisture contents (wet base) of about 18.30, 12.40, 9.20%; 15.35, 11.20, 9.00%, for rice and wheat respectively, and three different sieve speeds of 1100, 1500, 2000 rpm corresponding to 5.75, 7.85, 10.46 m/s for both rice and wheat grains . The results show that the highest machine productivity and cleaning efficiency were 0.22, 0.23 Mg/h and 86.0, 92.5% for rice and wheat, respectively. While the lowest specific energy and operating cost were 1.31, 1.22 kW.h/Mg and 84.0, 80.0L.E/Mg, for rice and wheat grains, respectively. These results were achieved under the following conditions: feed rate of about 0.204 Mg/h and sieve speed of 1500 rpm (7.85m/s),  moisture content of 9.20% and 9% for rice and wheat, respectively and constant sieve inclination angle of 8 degree