Stress in molybdenum films deposited by ion beam sputtering has been studied as a function of deposition parameters, such as accelerating voltage, incident angle, and chamber pressure. It has been found that the physical properties of deposited molybdenum films controlled primarily by the ion beam accelerating voltage and substrate orientation with respect to the ion beam. For films deposited at near normal incidence, measured stresses are highly compressive (2–5 GPa) and increase almost linearly with the accelerating voltage (600–1500 V). Under these conditions, deposited molybdenum films exhibit low resistivity and high optical reflectance. As the substrates are rotated to near grazing incidence, measured stress is either negligible or slightly tensile and are almost independent of accelerating voltage. The extremely high resistivity and low reflectance measured indicates the poor quality of the deposited film at grazing incidence. No significant effect was observed when the chamber pressure was varied between 7×10−5 and 5×10−4 Torr. The observations are interpreted by ‘‘structure zone model’’ and ‘‘atomic peening mechanism’’ (forward sputtering and recoil damage to the depositing films) previously proposed for films prepared by conventional sputtering and evaporation.