FSP is a relatively new technique that changes the microstructure on the surface of the material to improve mechanical properties in the desired zone. This study aimed to investigate the surface quality of AA2098 sheets after being subjected to friction stir processing under different conditions of feed rate and rotational speed. A DoE analysis was developed with two factors, feed rate and rotational speed, and three different levels of 75, 100, 125 mm/min and 1000, 1250, 1500 rpm respectively, in order to assess the processed surface quality. The Sa parameter was used to represent the surface quality in different zones of the process, near entrance tool, middle and near exit tool, and ANOVA analysis was conducted. The results indicated that only the position and feed rate have a statistical influence on surface roughness. Additionally, the surface quality is strongly affected by the position relative to the entrance of the tool and the side (retreating or advancing sides). The roughness was found to be significantly lower on the advancing side rather than on the retreating side.