Calix[4]resorcinarene-derived surfactants are highly effective at stabilizing metal nanoparticles of different sizes, creating opportunities to fabricate well-defined nanostructures with size-tunable materials properties. The resorcinarenes have a critical role in the dispersion of nanoparticles under various solvent conditions and in the robustness of the protective surfactant layer. Magnetic cobalt particles stabilized by resorcinarenes self-assemble into nanostructured "bracelets" in toluene. Resorcinarene surfactants can also promote the self-organization of gold nanoparticles as large as 170 nm into two-dimensional arrays. These nanostructured films possess novel optoelectronic properties such as surface-enhanced Raman scattering (SERS), and are expected to have useful applications for chemical sensing.