The electroless plating of silver films on pure silver nanoparticle seed layers prepared by spin-coating and thermal decomposition of PVP/Ag nanoparticle composite has been investigated. The plating results strongly depend on the agglomeration of nanoparticles and interparticle distances in the seed layer, which in turn crucially depend on the thermal processing parameters. Uniform nanocrystalline 200-nm-thick silver films on glass were prepared by plating on nanoparticle layers with surface density of 5.7 × 10 10 cm- 2 and average particle size of 40 nm. It is shown that electroless plating on nanoparticle seed layers can produce different surface structures and can finely tune the surface plasmon resonance in nanoparticle layers that can be useful for optical and sensing applications. © 2005 Elsevier B.V. All rights reserved.