This book highlights the optimization of Nd:YAG Laser welding by using Taguchi method based GRA. The aim of this research is to optimize and predict Nd: YAG laser welding process parameters with multiple quality characteristics of economically important materials in industry through application of Taguchi method based Grey Relational Analysis as a DOE approach to design the experiments and optimize the welding operation. This was achieved by controlling selected welding parameters, such as, laser pulse width, pulse height, frequency, welding speed, shielding gas flow rate, shielding gas flow angle and focus position, and thereafter, to analyse the influence of these parameters on the weld bead geometry and the mechanical properties of the welds. The material was investigated in this work was AISI 304 SS. The analysis of variance (ANOVA) is also employed to determine the contribution of each control parameter on the welding quality characteristics. For each welded joint, the main effects and the interaction effects of the process parameters on the responses were discussed and presented graphically.