In the present paper we aim to present a numerical optimizing study on the operating conditions of an atmospheric plasma spraying process. The focus is mainly made on the powder injection parameters and the objective is to improve the quality of surface coatings. First, a ‘validation’ test of the Jets&Poudres code is conducted based on various numerical and experimental former works. The results of the Jets&Poudres code seem to be a good compromise between the results of different numerical methods and the experimental measurements. Second, a Taguchi experimental design is conducted to explore the influence parts for five operating parameters in the spraying process. This, results in a primary gas flow rate of 45 SL/min, a spray distance of 12 cm, a particle size around 55μm, a powder feed rate ranging close to 1 l/min and finally an electric power of about 25 kW. Finally, a test case for a ternary gas mixture is conducted on 15000 particles using the Jets&Poudres code to assess the conclusions drawn in the studies using the experimental design. The results are confronted together and discussed.