In this paper, an attempt has been made to optimize the FSW parameters to acquire the minimum defects area. For this purpose, 1080 Aluminum plate were welded by FSW in different welding parameters. The experimental design was done with the Taguchi L9 orthogonal design. The selected parameters involving tool shape, tilt Angle, welding speed and rotational speed were defined as statistical design of experiment (DOE) and the defect area was defined as the response parameter. The optimum process parameters and their effectiveness on the response parameter (defects areas) were studied through the experimental design tools such as S/N ratio and ANOVA tests. The results proved that the tilt angle and tool shape have the most influence on the welding process. The welding condition that leads to minimum defects has been defined as the optimal welding condition. The optimal process performance could be acquire by cylindrical tool shape and 3 degrees title angel while the welding speed and rotation speed are preferred to be 250 mm/min and 450 rpm, respectively.