The study deals with statistical optimisation of the input parameters required for the implementation of mask-less milling of AISI 304 using abrasive waterjet technology. In this study, the effect of traverse speed (1000 and 3000 mm/min), abrasive flow rate (100 and 200 g/min) and standoff distance (4 mm and 15 mm) for a step-over distance of 0.6 mm were studied on the output responses of width, depth, surface roughness parameter (Rz). A total of 8 experiments using full factorial design were performed, and the experimental results were analyzed using the Minitab software. The results demonstrated that the maximum possible width is achieved by the execution of lower traverse speed, higher abrasive flow rate and higher standoff distance; the maximum possible depth is achieved by the execution of lower traverse speed, higher abrasive flow rate and lower standoff distance; and the execution of higher traverse speed, higher abrasive flow rate and lower standoff distance achieves the minimum possible Rz. By performing ‘desirability approach’ optimization, the optimum parameter configuration was found to be a traverse speed of 1622 mm/min, abrasive flow rate of 200 g/min, and standoff distance of 4 mm. The study concludes that the utilization of multiple input variables within the experimental domain to achieve more accurate results as per the desired output requirements.