Hybrid transparent coatings based on zirconia nanoparticle fillers and epoxy resin were designed to increase scratch resistance of commodity polymers without impairing their optical properties. Suspensions of nano-crystalline ZrO2 in benzyl alcohol were synthesized via a versatile non-hydrolytic sol-gel process using ZrCl4 as precursor. The obtained ZrO2 nanoparticles showed a crystalline structure attributable to a tetragonal phase and an average particle size of 2 nm. ZrO2 nanoparticles, suspended in tert-butanol, were mixed with a commercial epoxy resin (5 and 10%wt.). The organic solvent was then evaporated and hybrid composites were deposited on polycarbonate and poly(methyl methacrylate). The obtained coatings showed a homogeneous adhesion and a negligible effect on the transparency of these polymers. An increased scratch-resistance was obtained by increasing the ZrO2 nanoparticles content.