Superlattices formed by arrays of Pt or Flu nanoparticles have been obtained by layer-by-layer deposition by using dithiols as cross-linkers. The superlattices have been characterized by X-ray diffraction, photoelectron spectroscopy, and scanning tunneling microscopy. The core-level intensities of the metal and of the dithiol in the X-ray photoelectron spectra show the expected increase with successive depositions. The formation of such structures has been confirmed by depositing Pt and Au layers alternatively. Layers of metal and CdS nanoparticles have been deposited alternatively to obtain heterostructures.