This article reveals the influence of laser welding process parameter, welding speed, on the mechanical and metallurgical properties of 3.5 kW CO 2 laser machine welded joints of 70/30 Cu-Ni alloys. Laser welded joints were fabricated using different welding speeds of 1.0, 1.5, 2.0, and 2.5 m/min. The mechanical properties (hardness, tensile strength, and percentage elongation) of the welded joints were evaluated and correlated with the fusion zone microstructure. Optical microscopy and scanning electron microscopy were used to evaluate the metallurgical characteristics of the welded joints. The joints fabricated using a welding speed of 1.5 m/min exhibited fine, equiaxed, and uniformly distributed grains at fusion zone and resulted in superior mechanical properties than other joints.