The effect of ion irradiation on the crystallization of the nickel films prepared by the ion beam and vapour deposition (IVD) method was studied. The nickel films were prepared on the silicon (100) wafers by evaporation of nickel and simultaneous irradiation with inert gas ions, such as neon, argon, krypton, and xenon. The energy of inert gas ion bombardment was changed in the range 0.5-10.0 keV. The crystallization states of the films were analyzed by x-ray diffraction. X-ray diffraction patterns indicated that the (111), (200) and (220) crystallinity depended strongly on both ion beam energy and ion species. We studied the effect of ion irradiation on the crystallization of nickel films in terms of stopping cross-section of the ions. It seems that in the case of ion irradiation which is dominated by the nuclear stopping cross-section, the crystallization of the (111) orientation is promoted strongly; as and as the effect of the electronic stopping cross-section increases, the orientation of the crystallization is changed in the order of (100) and (110).