Ordered arrays of polystyrene nanospheres were self-assembled on glass substrate and subsequently used as templates for thin silver film deposition. Silver-polystyrene nanocomposites with periodicity given by the polystyrene spheres diameter (400 nm) were obtained and investigated by optical measurements and electron microscopy. The resonant interaction of light with surface plasmons supported by periodically structured silver-polystyrene nanocomposite leads to important spectroscopic applications like molecular sensing and enhanced Raman scattering.