Nanocrystalline Cr–C layers with excellent anti-wear performance were prepared by electrodeposition in Cr 3+ bath and subsequent annealing. X-ray diffraction (XRD) shows that the crystalline structure of the Cr–C layer changed from amorphous to nanocrystalline when the annealing was conducted. The hardness, Young's modulus and wear rate of the Cr–C layer were measured. The results indicate that the 400 °C-annealed nanocrystalline Cr–C layer exhibits a high ratio of hardness to Young's modulus and excellent wear resistance. The excellent wear resistance can be attributed to the proper compromising of hardness and toughness. The friction tests reveal that the friction coefficient depends on the Young's modulus and the counterpart. Comparing wear with friction, no obvious connection can be found between them.