The influence of low-energy ion bombardment on the texture and microstructure of an 80-nm-thick Pt film deposited at room temperature was investigated. The treatment was carried out in inductively coupled Ar plasma with a negative bias of 45–125 V applied to the specimens and an ion current density of 3.3 mA/cm2. As a result of a series of treatments at each bias, the film was thinned; after each treatment, its structural parameters were determined using X-ray diffraction and compared with those of Pt films 20–60 nm thick deposited under the same conditions. Treatment at 75–125 V led to a decrease in the average size of coherent scattering regions by 10–25%; in the 45 V mode, such a decrease was not observed. These results were explained by the formation and accumulation of radiation defects, the rate of their generation was lower at bias of 45 V. Film sputtering in all modes did not worsen the sharpness of the film texture.