We report the optical absorption of a multilayer system and the electrical properties of silver (Ag) naoparticles (NPs) embedded on LiNbO3 that acts as active layer. The multilayer system is constituted by Indium Tin Oxide (ITO), a square lattice of Ag NPs on the uniaxial crystal LiNbO3, the polymer PMMA and a substrate of SiO2. The effective dielectric function of the ensemble aggregates of Ag NPs and uniaxial LiNbO3 crystal are treated through the extended Maxwell–Garnett approximation. The multilayer absorbance for s- and p-polarization at normal and oblique incidences is determined by means of the Transfer Matrix Method. We demonstrate that an adequate choice of structural parameters such as NPs sizes, interparticle distances and layers thicknesses can produce an enhancement of optical absorption in the multilayer system. For filling factor higher, the system absorbance is greater. The Brewster angle is seen to be sensitive to the Ag NPs size, as far as the wavelength is varied. In addition, we evaluate the dielectric modulus parameter and the ac–electrical conductivity of the effective medium layer (active layer) in the perpendicular and parallel directions of the Ag NPs plane. For both directions, at f sufficiently high, we find the negative epsilon condition, typical characteristic observed in metamaterials. For the ac–electrical conductivity, we identify different resonances for the perpendicular and parallel directions. A bigger concentration of Ag NPs induces a higher intensity of ac–conductivity.