Laser beam welding (LBW) is a field of growing importance in industry with respect to traditional welding methodologies due to lower dimension and shape distortion of components and greater processing velocity. Inconel 625 and duplex stainless steel SAF 2205 are used in geothermal, marine, oil and gas applications, owing to its high tensile strength and corrosion resistance property. This work aims to investigate the effect of welding speed on different process parameters in laser welding for Inconel 625 and duplex stainless steel SAF 2205 plate. A statistical design of experiment (DOE) is utilized to develop an effective model to optimize weld strength and weld geometry by incorporating process parameters, such as traveling speed, laser power and focal position. The microstructure of the weld beads was examined using a combination of optical microscopy, scanning electron microscopy (with energy dispersive X-ray analysis). In this work an effective methodology is developed to determine the optimum welding condition. From the results, appropriate welding speed and processing conditions can be selected to obtain optimum welding.