Cr–N coatings were deposited using the ion-beam-assisted magnetron sputtering technique. The microstructure and mechanical properties of Cr–N coatings were found to be dependent on the ion bombardment energy. The microstructure of the coatings changes from columnar structure to fine and dense grains when the ion bombardment energy increases from 0 to 800eV and to equiaxial grains for an ion energy of 1200eV. The coatings average grain size, which is determined by the Voigt profile function, decreases from 20.3nm at an ion energy of 0eV to 8.8nm at 800eV and further increases to 21.5nm at 1200eV. Both the hardness and fracture toughness of the coatings are improved when the ion energy increases from 0 to 800eV, which is related to the decrease of grain size. The grain size of the coating grown at an energy of 1200eV is close to that of 0eV, but the hardness and fracture toughness at 1200eV are higher. This suggests that the improvement of hardness and fracture toughness is also related to the increased densification of the coatings caused by ion bombardment.