A dual-cathode, unbalanced de magnetron sputtering system was used to grow CNx/ZrN multilayers on Si and polished M1 steel substrates at ambient temperature. Nanoindentation results showed that, under apprepriate conditions, it is possible to get CNx/ZrN multilayer coatings with hardness in the 50 GPa regime and modulus up to 410 GPa. X-ray diffraction studies revealed a strong correlation between hardness and the occurrence of (111) texture of ZrN. Cross-sectional transmission electron microscopy showed a high degree of crystallinity throughout the coating without obvious voids. These multilayers are crystalline only at small bilayer thicknesses on the order of 2 nm.