A series of polymer-coated Au nanoparticles have been prepared using the “grafting-to” approach. Thiol-terminated polystyrene and poly(ethylene oxide) ligands are found to form dense brushes on the facetedgold nanoparticle surfaces. Depending on the polymer, the ligand grafting densities on the gold nanoparticlesare 1.2- to 23.5-fold greater than those available via self-assembled monolayer formation of the correspondingtwo-dimensional gold surfaces.