Cemented carbides are composite materials comprising metal carbide grains in a more ductile metallic binder. This microstructure results in a combination of high hardness and toughness, making them commonly used as rock crushing parts in rock drilling, where they usually show wear on a very fine scale. The hardness and toughness can ultimately be tuned for the application by adjusting the carbide grain size, binder fraction and composition.In the present investigation, the initial micro-scale deformation and wear of polished cemented carbide surfaces is studied by micro scratching with diamond and granite styli, and also by instrumented micro and nanoindentation. The deformation and wear is evaluated on the sub-micrometer scale using high resolution FEG-SEM and FIB cross sectioning. The selected microstructures include besides four cemented carbide grades that are commonly used in rock drilling also binderless and Ni containing grades. This wider range of cemented carbides is used to gain fundamental insights into the relations between microstructure and micro-scale deformation and wear. The results are discussed with respect to their significance for wear of cemented carbides in rock drilling operations.