The main objective of the present work is to develop a low–cost mechanical washer and drying of a small-scale washing machine to reduce the labor and time requirements for these two processes. Mandarin fruits (variety of Ponkan) and potato tubers  (Diamant variety) were used for the experimental work. Design considerations and operating constraints included: nozzle water pressures ranging from 0.3 to 0.4 MPa (3 to 4 bar), air speeds ranging from 2 to 4 m/s, operating speeds ranging from 0.45 to 0.85 m/s and different nozzle numbers ranging from 20 to 28. Physical and mechanical properties of the studied fruits, cleaning efficiency, removed water efficiency, mechanical damage; operating cost and productivity were studied to evaluate the performance of the developed washing machine. The obtained results indicated that the optimum performance of the developed washing machine was at operating speed of. 0.65 m/s, nozzles water pressure of 0.4 MPa (4 bar), number of nozzles 28 and drying air speed of 4 m/s .Cleaning efficiencies at these conditions were 98.33 and 94.40 %, removed water efficiency values (by sponge rollers and blower fan) were 96.23 and 97.87 %, mechanical damage percentages were 1.15 and 1.95 %, operating costs were 1.92 and 2.47 L.E/Mg, and machine productivity values were 4.75 and 2.44 Mg/h for mandarin fruits (variety of Ponkan) and potatoes (Diamant variety), respectively.