Friction stir welding (FSW) is a modernistic solid-state welding technique which characterized by an environmentally friendly process. This paper focuses on the effect of tool rotational speed and welding speed on surface roughness of AA 6063 FSW joints. Four rotational speeds and three welding speeds were used in FSW trials. Surface roughness tests are carried out and reported at start, center and end of all weld joints. The surface roughness test results show that the tool rotational speed and welding speed are very important to control the surface quality of welded joints. The rotational speed had displayed a higher significant effect on the surface roughness of the weld joints than the welding speed. At high tool rotational speed 470 RPM and low welding speed 160 mm/min, the best surface roughness quality obtained as 7.990 μm.