The fabrication of transparent nanocomposites with enhanced mechanical properties employing highly stable ZrO2 nanoparticle dispersions is reported. The dispersions were obtained via chemical stabilization directly after the nanoparticle synthesis involving simple stirring at room temperature. The nanocomposites obtained by embedding the nanoparticles from these dispersions in epoxy resins show substantially enhanced mechanical properties with increases of up to 11% in ultimate tensile strength and 11% Young's modulus, which however are strongly dependent on the method of embedding.