The main objective of this research work is to investigate the feasibility of Friction Stir Welding (FSW) of AA7075 T6 and AA2024 T3 dissimilar aluminum alloys, with thickness ratio of 1.3, and to investigate the mechanical and structural properties of the weld. Since both AA2024 T3 and AA7075 T6 are not weldable by fusion welding processes, FSW process is used to weld both of these dissimilar alloys. Defect-free, tailor weld blanks were produced on the plates of AA7075 T6 and AA 2024 T3 having thickness of 6.5 mm and 5 mm respectively. The process parameters employed in this study include the tool rotation and travel speeds. The FSW tool employed in this study was made using AISI H13 tempered steel with square pin profile having pin diameter of 5 mm, concavity at pin start of 1 mm and pin length of 4.85 mm. The welded plates have been characterized for their mechanical and metallurgical properties. The effects of tool rotational speed and the welding speed on the joint performance were discussed.