SiO2-based inorganic-inorganic hybrid sonogels were prepared with Au/SiO2 supported nanoparticles (NPs). The well-established catalyst-free (CF) sonogel route was successfully implemented to produce these optically active nano-composites by doping the liquid sol-phase with Au/SiO2-NPs synthesized according to the [Au(en)(2)](3+)-cation-adsorption method. Prepared Au/SiO2-NPs exhibited low 2D-HCP crystallinity with particle diameters below 10 nm and homogeneous size distribution. The easy Au/SiO2-NPs loading within the mesoporous dielectric sonogel network evidenced the huge chemical affinity between the highly pure CF-sonogel host and the guest Au/SiO2-NPs. This fact allowed us to fabricate rigid monoliths with controllable geometrical shapes suitable for optical characterizations. Indeed, the host system provided thermal and mechanical stability protecting the active metallic NPs from environment conditions and diminished their tendency to from aggregates, thus, preserving their pristine optical properties and producing sol-gel hybrid glasses appropriate for optical applications. Comprehensive morphological, structural, spectroscopic, photo-physical and nonlinear optical (NLO) characterizations were performed on the obtained hybrids. Results show that Au/SiO2-NPs were homogeneously embedded within the highly pure SiO2-sonogel network. The crystalline nature, random orientation and small sizes of the Au/SiO2-NPs, together with the guest-host bulk interactions, allowed the observation of improved spectroscopic and quadratic NLO-properties for the developed amorphous-based hybrids. (C) 2010 Elsevier B.V. All rights reserved.