The present study concerns understanding the role of mechanical milling (aimed at the development of nano-crystalline structure) and spraying techniques (High Velocity Oxy-Fuel (HVOF) and Air Plasma Spray (APS)) on the microstructure and wear behavior of CoNiCrAlY coatings (in unmilled and milled state) developed on Inconel 718 substrate. The role of polishing of the deposited coating on the microstructure and wear behavior was also investigated. The coatings developed by both techniques exhibited γ (Co, Ni, Cr), γ'(Co, Ni)3Al, and β (Co, Ni)Al phases in the microstructure. HVOF-deposited coatings showed increasing microhardness with increasing milling time (290-800 VHN), whereas APS-deposited coating showed a decreasing trend with increasing milling time (450-550 VHN). In HVOF-deposited coatings, the wear rate was found to be significantly reduced with an increase in milling time. Polishing of the coating was found to influence the wear rate. In APS-deposited coatings, the wear rate was always reduced due to polishing for both milled and unmilled samples, though it does not follow any specific trend with milling hours. In HVOF-deposited coatings, the wear rate decreased with polishing for the coatings with milled powder; however, it increased due to polishing in coatings with unmilled powder. The study demonstrates that mechanical milling does not uniformly improve hardness or wear resistance, as its influence is strongly dependent on the thermal spray technique. Likewise, polishing—commonly assumed to enhance wear behavior—may instead reduce wear performance depending on the powder state and deposition method. The contrasting wear responses observed in HVOF and APS-deposited coatings arise from the distinct microstructural evolutions introduced during milling and spraying. These outcomes collectively establish that optimizing CoNiCrAlY coating performance requires a balanced integration of powder refinement, deposition technique, and post-treatment conditions.