Zirconium nitride thin films were prepared by ion-beam assisted deposition (IBAD) on silicon substrates. The films were synthesized by depositing zirconium vapor simultaneous irradiation with nitrogen ions. Transport ratio of Zr to N was varied between 1.0 and 3.0, and N-ion beam energy was kept 0.5 and 1.0 keV. The films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Hardness of the films was investigated with a nano-indentation tester. The films were tested for friction and wear on a ball-and-disk tribometer, under 5 N load and 10 mm/s relative sliding speed with steel balls as the counter material. The hardness of the films increased with decreasing the transport ratio. Tribological properties of films were compared with post chlorine-ion implanted films.