Wear mechanisms of air plasma-sprayed WC-12%Co coatings were studied by using a dry sand rubber wheel (DSRW) abrasive, ring-on-square adhesive wear, and alumina particle erosion tests. Coating properties such as intersplat cohesive strength, porosity, surface roughness, hardness, and retained carbide as well as microstructures were characterized to assess their relationship on wear performance. Porosity, hardness, surface roughness, and retained carbide of the coatings are not the principal factors affecting wear performance. Intersplat cohesive strength of coatings, measured by a simple bonding test, is the most significant factor that relates to the wear rate of thermal spray coatings.