Nanostructured alumina coatings have been deposited on SS 304 substrate using atmospheric plasma spray process. In the present work, nanostructured feed powder is obtained by manual granulation of nano-Al 2O 3 powder particles followed by exhaustive sieving, which is helpful in their proper consolidation. The tribological performance of the nano-alumina coatings, such as dry sliding, slurry erosion and cavitation erosion, has been investigated and compared with conventional coatings. The superior wear and erosion resistance of nanostructured coatings as compared to conventional coatings are due to its higher hardness and effective hindrance to crack propagation. Wear mechanism was explained based on their microstructure and worn surface morphologies. The microhardness and porosity of the two coatings were also experimentally investigated. © 2012 Institute of Materials, Minerals and Mining.