Electrical as well as photoelectrical properties of the metal nanoparticle ensembles (MNEs) were investigated. The exponential temperature dependence of the conductivity in the MNEs was obtained. Since lnIc depends linear on 1/T, an activation energy concept of the conductivity can be applied. An activation energy of Eact = 0.50 eV for Ag nanoparticles has been extracted. The photoconductivity of MNEs has been related to their extinction spectra. A clear evidence of the photoinduced conductivity of the MNEs was obtained. Considerable enhancement of the photocurrent was observed for those wavelengths that are in resonance with plasmon excitations localized in the metal nanoparticles forming the MNE. The increased photoconductivity can be explained by the additional energy placed in the nanoparticles due to the excitation of an LSPPR.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.