Presently for various engineering applications AA6061-T6 aluminum-magnesium alloys are widely preferred, which is due to its light weight and superior properties as compared to other aluminum alloys. The metal joining process is most complex in various industrial applications like automobile, aerospace, railway and marine. The Friction Stir Welding (FSW) of AA6061-T6 alloy has influenced substantial scientific and industrial importance, because it has a potential to transform the welded product with a good quality joint. In the present work AA6061-T6 alloy joined using FSW process. Observation has been made about material flow behavior and effect of process parameters on various mechanical properties and associated defects during FSW. From experimental results it can be concluded that FSW can be used to produce defect free welds, with better bending properties as compared to the welds produced by other conventional welding process.