The properties of polymeric materials have been enhanced by developing nanocomposites in several projects at the Technical Research Centre of Finland VTT. The improvement of conductivity, dielectric, mechanical properties and the thermal stability of polymer materials opens new application potential in electronic industry. In this paper the results of several projects are presented. By applying nano-POSS particles in polypropylene and epoxy the break down voltage was increased by 10 - 20%. The use of carbon nanotubes in polyaniline enhanced the conductivity by two decades compared to the commercially available polymers.