To explore the W nanoparticles effects on the subsurface microstructural self-organization of Cu-Ag two-phase alloys and the resulting wear performance, we have fabricated bulk nanostructured Cu-10 at% Ag-10 at% W ternary alloys by high energy ball milling and warm pressing. During ball milling, Ag is dissolved into the Cu matrix but W remains immiscible. Compaction of the powders into bulk at 300 °C leads to the Ag precipitation. The as-pressed Cu-10 at% Ag-10 at% W ternary alloy has Ag-rich precipitates size (d) of 22 nm and W particles size (d) of 26 nm. Further annealing at 600 °C for 1 h only increases d and d to 52 nm and 41 nm, respectively. The fabricated Cu-10 at% Ag-10 at% W ternary alloys thus demonstrate enhanced coarsening resistance. The two alloys were then subjected to dry sliding wear against stainless steel disks. It is found that the initial length scale of Ag-rich precipitates and W particles has a profound influence on the microstructure evolution during wear and accordingly on the wear performance. For the as-pressed sample with small d and d, severe plastic deformation (SPD) by wear forced the formation of Cu-Ag homogeneous solid solution, leading to low wear resistance. In contrast, for the annealed one with relatively large d and d the Cu, Ag and W three phases co-existed but the Ag-rich precipitates were transformed into wavy nanolayers, providing enhanced wear resistance. Compared with Cu-Ag alloys subjected to sliding wear, the presence of W nanoparticles was found to hinder the formation of self-organized nanolayered structure and leads to a small deformation depth. The obtained results provide deep insights into the plastic deformation mechanisms in ternary alloys and the design of wear resistant engineering materials.