Metal Inert Gas (MIG) welding is one of the most frequently used welding processes in various industrial applications. Welding current, voltage and inert gas CO flow rate have been considered as process parameters to optimize and their 2 effects on welding quality have been studied. Tensile strength of welded joint increases with increase in voltage, then it decreases. However, tensile strength increases with current and gas flow rate up to optimum values, then it decreases. The S/N ratio for all responses is calculated using MINITAB-17 software. The values of observed responses and S/N ratio for welded zone hardness, which shows that maximum welded zone hardness is 91 at 140 A welding current, 20 V welding voltage and 0.366 cm/second welding speed. The maximum S/N ratio of welded zone hardness is 39.1808 at optimum process parameters. For HAZ, maximum welded zone hardness is 87 at 160 A welding current, 24 V welding voltage and 0.536 cm/second welding speed respectively. The maximum S/N ratio of HAZ hardness is 38.7904 at optimum process parameters for HAZ. Maximum Ultimate Tensile Strength is 500 N/mm² at optimum process parameters respectively. The maximum S/N ratio of tensile strength is 53.9794 at optimum process parameters. Taguchi method is used successfully to analyse and determine the optimum process parameters to maximize HAZ hardness, welded zone hardness and tensile strength in MIG welding process.