Thermal barrier coatings (TBCs) functioning in the aviation and power generation industries have heavily relied on plasma sprayed yttria stabilized zirconia (YSZ) on MCrAlY bond coated engine components. Among those factors which may impact the repeatability and reliability of a TBC coating, powder feedstock is one of the most important while being the challenging to control constituents as it is difficult to keep the powder chemistry, morphology and size distribution exact the same from lot to lot, year after year. In this study the authors systematically vary the size distribution of one type of commercial YSZ powder to explore the effect of the size distribution on the TBC deposition and the coating performance. Deposition rate and efficiency are quantitatively compared for those experimental powders. The coating microstructures and performances for different sizing are also evaluated analytically. Understanding the impact of the powder variation on the coating deposition and performance is essential to determine the quality control standards.