Laser marking is one of the effective and efficient ways of permanent marking process in the different engineering materials like composites, ceramics and any other hard metals and alloys. The present investigation deals with the experimental analysis on laser marking process using diode pumped Nd:YAG laser considering several process parameters for example lamp current, pulse repetition rate and laser scanning speed. The Response Surface Methodology (RSM) based experimental design was adopted to study in-depth the influence of these parameters on marking performance criteria such as mark width, mark depth and mark intensity. Based on experimental results, the second order mathematical models were established. Multi performance optimized parametric combination was achieved to obtain high quality marking using developed models and desirability functions. Moreover, in order to determine the most influencing parameter on the responses, Sensitivity Analysis (SA) was performed on the test results obtained from experimentation as well as predictive models. SEM and optical microscopic images were also analyzed to examine the quality aspects of laser marking on gallium nitride.